Tagged research

Breast Cancer Centers Urge Annual Scans, Counter to U.S. Guidelines

A panel recommends biennial screenings, starting at 50, but a new study took issue with the way hundreds of centers are telling women 40 and up to come in yearly. Some experts contend that frequent mammograms can “do more harm than good.”

My last breast cancer screening was “b.c.” — before Covid — just a few weeks before the mysterious new disease was detected in China. The timing was perfect: Everything was normal, and by the time we went into lockdown, my to-do list no longer included a mammogram.

But by November 2020, exactly one year after that scan, I started getting barraged by phone calls and text messages telling me I was due for another one.

“MAMMO MATTERS,” screamed one in all capital letters. “Breast cancer does not take a break during pandemics, and neither should you.” I was well aware that national health guidelines recommend a mammogram only every other year for women at average risk for breast cancer. But there has been a cacophony of advice in recent years as different groups recast their recommendations, often contradicting one another. So the messages were unnerving.

It turns out my imaging center is not alone in badgering women to have mammograms more frequently than the U.S. Preventive Services Task Force deems optimal. A recent study found that hundreds of breast centers tell women who are not at elevated risk of cancer to have a routine scan every year, and to start at 40.

The task force, however, recommends regular mammograms every two years starting at 50. Its guidelines do recommend that women in their 40s discuss mammography with their doctors, evaluate the risks and benefits and come to an individual decision. (The panel’s recommendations extend to age 74; it has said there is not enough evidence to make recommendations past that age.)

The new study, published in JAMA Internal Medicine on March 15, was accompanied by a rather scathing editorial that said extra screening can do “more harm than good.”

“I don’t think breast cancer centers that have clear financial benefits from increasing mammography should be the ones that are giving out patient advice, particularly when it conflicts with the patient’s primary care provider’s advice and the task force’s advice,” said Dr. Rita F. Redberg, editor in chief of JAMA Internal Medicine, who co-wrote the editorial along with Dr. Anand R. Habib and Dr. Deborah Grady.

The American College of Radiology took umbrage, shooting back that it was “outrageous” to assert that breast cancer centers were promoting mammograms for financial reasons, and that the radiologists’ had a different set of guidelines.

When the pandemic started, both routine screenings and appointments triggered by troubling symptoms like the discovery of a lump were delayed as facilities shut down. Even when they reopened, many patients were reluctant to go in.

But Dr. Dana Smetherman, who chairs the American College of Radiology’s breast imaging commission, said the breast centers’ recommendations for more frequent screening predate the pandemic.

“What this study is telling us is that the experts in breast cancer in the U.S. do not support these recommendations,” Dr. Smetherman said in an interview, referring to the U.S. task force’s guidelines.

Indeed: Both the college of radiology and the American Society of Breast Surgeons recommend annual mammograms starting at age 40 (Dr. Redberg’s institution, the University of California, San Francisco, also recommends that schedule).

The American Cancer Society scaled back its recommendations recently, however, endorsing yearly scans starting at age 45, with the option of switching to every other year at age 54. The American College of Obstetricians and Gynecologists recommends women at average risk start mammography at 40, but “every one or two years.”

The debate over screening frequency for breast cancer — the second leading cause of cancer death for women after lung cancer — dates back to 2009. That is when the U.S. Preventive Services Task Force, an independent expert panel that reviews the evidence and provides guidance to doctors and insurers, rolled back its mammography recommendations for women who were deemed at average risk for breast cancer.

Screening can actually be harmful, especially for younger women, the panel found. False positive findings can trigger unnecessary procedures like biopsies, or lead to what experts call over-diagnosis — the aggressive treatment of slow-growing tumors that might never become life-threatening, but cannot be distinguished from fast-growing tumors.

When women had mammograms every other year, the harms of false positives and unnecessary treatment were reduced, the panel determined, while it found the life-saving benefits remained relatively unchanged.

But some experts believe the panel overstated the harms of more frequent screenings. The appropriate schedule for screenings can vary from doctor to doctor, and patient to patient, and has become quite confusing.

“Many women may not even be aware of the guidelines, or that there may be any downside to mammography, and that they have the option to begin screening at age 45 or 50,” Dr. Jennifer L. Marti, an assistant professor of surgery at Weill Cornell Medicine who led the new study, said in an interview. “In almost every other country, women start at 50.”

While many women might assume that “the pros of breast cancer screening outweigh the harms,” Dr. Marti said, that is not always the case for women who aren’t at elevated risk.

Dr. Marti and her co-authors, Mark Lee and Neal Patel, two Weill Cornell researchers, decided to examine the recommendations posted on the websites of some 606 breast cancer centers in the United States. They found that 376 centers — over half — made recommendations that differed from those of the U.S. task force, saying women at average risk for breast cancer should start imaging at age 40.

And 347 centers said women should not only start at 40, but continue annually.

More rigorous screening may be appropriate for some high risk groups, like Ashkenazi Jewish women, who are more likely to carry mutations that put them at risk for breast and ovarian cancer, and Black women, who were likely underrepresented in mammography screening trials, Dr. Marti said.

Women who want help assessing their individual risk to make screening decisions can use an online tool developed by Dr. Margaret Polaneczky, a gynecologist from Weill Cornell Medicine, and Elena Elkin, a research scientist at Memorial Sloan Kettering Cancer Center, Dr. Marti suggested.

As for myself, I’ve been on a two-year plan for a while. I do regular breast self-examinations, and have clinical breast exams too. So even though I felt a smidgen of irrational guilt after receiving the text messages, I politely asked a receptionist to please stop calling. I promised I’d be in touch.

Many Children With MIS-C Had No Covid-19 Symptoms

Pediatricians should be vigilant, experts said, after the release of the largest U.S. study of the syndrome, MIS-C, that can strike young people weeks after their coronavirus infection.

Many children and teenagers who developed the mysterious inflammatory syndrome that can emerge several weeks after contracting the coronavirus never had classic Covid-19 symptoms at the time of their infection, according to the largest study so far of cases in the United States.

The study, led by researchers from the Centers for Disease Control and Prevention, found that in over 1,000 cases in which information about whether they got sick from their initial Covid-19 illness was available, 75 percent of the patients did not experience such symptoms. But two to five weeks later, they became sick enough to be hospitalized for the condition, called Multisystem Inflammatory Syndrome in Children (MIS-C), which can affect multiple organs, especially the heart.

Published Tuesday in JAMA Pediatrics, the study said that “most MIS-C illnesses are believed to result from asymptomatic or mild Covid-19” followed by a hyper-inflammatory response that appears to occur when the patients’ bodies have produced their maximum level of antibodies to the virus. Experts do not yet know why some young people, and a smaller number of adults, respond this way.

“It means primary-care pediatricians need to have a high index of suspicion for this because Covid is so prevalent in the society and children often have asymptomatic disease as their initial Covid infection,” said Dr. Jennifer Blumenthal, a pediatric intensivist and pediatric infectious disease specialist at Boston Children’s Hospital, who was not involved in the study.

The researchers evaluated 1,733 of the 2,090 cases of the syndrome in people age 20 and younger that had been reported to the C.D.C. as of January.

The findings show that although the syndrome is rare, it can be serious. The C.D.C’s data only included patients who were hospitalized. Over 90 percent of those young people experienced symptoms involving at least four organ systems and 58 percent needed treatment in intensive care units.

Many experienced significant heart issues: over half developed low blood pressure, 37 percent developed cardiogenic shock and 31 percent experienced cardiac dysfunction involving their heart’s inability to pump adequately. The study said that a significantly higher percentage of patients who had not had Covid-19 symptoms experienced those heart problems, compared with those who had initial coronavirus symptoms. A greater percentage of initially asymptomatic patients also ended up in intensive care.

“Even the kids with severe MIS-C, who were in the I.C.U. — the vast majority of them did not have a preceding illness that they recognized,” said Dr. Roberta DeBiasi, chief of infectious diseases at Children’s National Hospital in Washington, D.C., who was not involved in the research.

The study provided the most detailed demographic and geographic picture of the syndrome to date. About 34 percent of the patients were Black and 37 percent were Hispanic, reflecting the way that the coronavirus has disproportionately affected members of those communities. As the pandemic went on, the authors wrote, the proportion of patients who were white increased, comprising 20 percent of all cases. People of Asian heritage comprised just over 1 percent of patients.

Overall, nearly 58 percent of the patients were male, but the proportion was not the same across all ages. The youngest group — newborn to age 4 — had roughly equal numbers of boys and girls, and the male-to-female ratio increased in the older groups until it was more than two-to-one male to female in the 18-to-20 group.

The vast majority of patients (nearly 86 percent) were younger than 15. The study found that those under 5 had the lowest risk of serious heart complications and were less likely to need intensive care. Patients 10 and older were significantly more likely to develop issues like shock, low blood pressure and myocarditis (inflammation of the heart muscle).

“I think that’s similar to what we saw with Covid, that the older kids seemed to have more severe disease,” Dr. DeBiasi said. “And that’s because what makes people really sick from the Covid is the inflammatory aspect of it, so maybe these older kids, for whatever reasons, make more inflammation, whether that’s in primary Covid or MIS-C.”

Still, significant numbers of the youngest patients developed heart problems. In the newborn-to-4 age group, 36 percent had low blood pressure, 25 percent had shock and 44 percent were treated in the I.C.U.

Patients of all ages in the study had about the same occurrence of some of the less-common heart issues linked to the syndrome, including coronary aneurysms and fluid buildup. Children 14 and under were more likely to have rash and red eyes, while those older than 14 were more likely to have chest pain, shortness of breath and cough. Abdominal pain and vomiting afflicted about two-thirds of all patients.

There were 24 deaths recorded, spread across all age groups. There was no information in the study about whether patients had underlying medical conditions, but doctors and researchers have reported that young people with MIS-C were often previously healthy and significantly more likely to be healthy than the relatively small number of young people who become seriously ill from initial Covid infections.

Of the 1,075 patients for whom information about initial Covid illness was available, only 265 had symptoms at that time. They were more likely to be older — their median age was 11, while the median age of those with asymptomatic Covid infections was 8. But that could be because “younger children can’t express their concerns as well,” said Dr. Blumenthal, who co-wrote an editorial about the study.

“We don’t necessarily know if there’s actually less symptomatology in the very young population, ” she said.

Similarly unclear are the reasons behind the study’s finding that in the first wave of MIS-C, from March 1 to July 1, 2020, young people were more prone to a few of the most serious heart complications. Dr. DeBiasi said that did not match the experience of her hospital, where “the kids were sicker in the second wave.”

The study documented two waves of MIS-C cases that followed surges in overall coronavirus cases by about a month or more. “The most recent third peak of the Covid-19 pandemic appears to be leading to another MIS-C peak perhaps involving urban and rural communities,” the authors wrote.

The study found that most of the states where the rate of MIS-C cases per population was highest were in the Northeast, which had the first surge of cases, and the South. By contrast, most states with high per-population rates of children with Covid-19 but low rates of MIS-C were in the Midwest and West. While the concentration of cases spread from large cities to smaller towns over time, it wasn’t as pronounced as the overall pandemic trends, the authors said.

Dr. Blumenthal said that geographic pattern could reflect that the “understanding of the complications of the disease” hadn’t caught up to its prevalence in different regions or that many states with lower rates of MIS-C have less ethnically diverse populations. “It could also be something about Covid itself, although we don’t know that,” she said. “Right now, we don’t know anything about how the variants necessarily affect children.”

The study represented only the strictest criteria for MIS-C, excluding about 350 reported cases that met the C.D.C. definition of the syndrome but had a negative antibody test or primarily involved respiratory symptoms. Dr. DeBiasi said there are also many probable MIS-C cases that are not reported to the C.D.C. because they don’t meet all the official criteria.

“These probable MIS-C kids, in real life that’s a big chunk of kids,” she said. In addition, while the focus so far has been on serious cases, “there’s another whole group of kids that may actually have mild MIS-C.”

If a community has experienced a recent coronavirus surge, then “just because the kid says, ‘I never had Covid or my parents never had it,’ that doesn’t mean the kid in front of you doesn’t have MIS-C,” Dr. DeBiasi said. “If your city has Covid, then get ready.”

Many Children With Serious Inflammatory Syndrome Had No Covid Symptoms

Pediatricians should be vigilant, experts said, after the release of the largest U.S. study of the syndrome, MIS-C, that can strike young people weeks after their coronavirus infection.

Many children and teenagers who developed the mysterious inflammatory syndrome that can emerge several weeks after contracting the coronavirus never had classic Covid-19 symptoms at the time of their infection, according to the largest study so far of cases in the United States.

The study, led by researchers from the Centers for Disease Control and Prevention, found that in over 1,000 cases in which information about whether they got sick from their initial Covid-19 illness was available, 75 percent of the patients did not experience such symptoms. But two to five weeks later, they became sick enough to be hospitalized for the condition, called Multisystem Inflammatory Syndrome in Children (MIS-C), which can affect multiple organs, especially the heart.

Published Tuesday in JAMA Pediatrics, the study said that “most MIS-C illnesses are believed to result from asymptomatic or mild Covid-19” followed by a hyper-inflammatory response that appears to occur when the patients’ bodies have produced their maximum level of antibodies to the virus. Experts do not yet know why some young people, and a smaller number of adults, respond this way.

“It means primary-care pediatricians need to have a high index of suspicion for this because Covid is so prevalent in the society and children often have asymptomatic disease as their initial Covid infection,” said Dr. Jennifer Blumenthal, a pediatric intensivist and pediatric infectious disease specialist at Boston Children’s Hospital, who was not involved in the study.

The researchers evaluated 1,733 of the 2,090 cases of the syndrome in people age 20 and younger that had been reported to the C.D.C. as of January.

The findings show that although the syndrome is rare, it can be serious. The C.D.C’s data only included patients who were hospitalized. Over 90 percent of those young people experienced symptoms involving at least four organ systems and 58 percent needed treatment in intensive care units.

Many experienced significant heart issues: over half developed low blood pressure, 37 percent developed cardiogenic shock and 31 percent experienced cardiac dysfunction involving their heart’s inability to pump adequately. The study said that a significantly higher percentage of patients who had not had Covid-19 symptoms experienced those heart problems, compared with those who had initial coronavirus symptoms. A greater percentage of initially asymptomatic patients also ended up in intensive care.

“Even the kids with severe MIS-C, who were in the I.C.U. — the vast majority of them did not have a preceding illness that they recognized,” said Dr. Roberta DeBiasi, chief of infectious diseases at Children’s National Hospital in Washington, D.C., who was not involved in the research.

The study provided the most detailed demographic and geographic picture of the syndrome to date. About 34 percent of the patients were Black and 37 percent were Hispanic, reflecting the way that the coronavirus has disproportionately affected members of those communities. As the pandemic went on, the authors wrote, the proportion of patients who were white increased, comprising 20 percent of all cases. People of Asian heritage comprised just over 1 percent of patients.

Overall, nearly 58 percent of the patients were male, but the proportion was not the same across all ages. The youngest group — newborn to age 4 — had roughly equal numbers of boys and girls, and the male-to-female ratio increased in the older groups until it was more than two-to-one male to female in the 18-to-20 group.

The vast majority of patients (nearly 86 percent) were younger than 15. The study found that those under 5 had the lowest risk of serious heart complications and were less likely to need intensive care. Patients 10 and older were significantly more likely to develop issues like shock, low blood pressure and myocarditis (inflammation of the heart muscle).

“I think that’s similar to what we saw with Covid, that the older kids seemed to have more severe disease,” Dr. DeBiasi said. “And that’s because what makes people really sick from the Covid is the inflammatory aspect of it, so maybe these older kids, for whatever reasons, make more inflammation, whether that’s in primary Covid or MIS-C.”

Still, significant numbers of the youngest patients developed heart problems. In the newborn-to-4 age group, 36 percent had low blood pressure, 25 percent had shock and 44 percent were treated in the I.C.U.

Patients of all ages in the study had about the same occurrence of some of the less-common heart issues linked to the syndrome, including coronary aneurysms and fluid buildup. Children 14 and under were more likely to have rash and red eyes, while those older than 14 were more likely to have chest pain, shortness of breath and cough. Abdominal pain and vomiting afflicted about two-thirds of all patients.

There were 24 deaths recorded, spread across all age groups. There was no information in the study about whether patients had underlying medical conditions, but doctors and researchers have reported that young people with MIS-C were often previously healthy and significantly more likely to be healthy than the relatively small number of young people who become seriously ill from initial Covid infections.

Of the 1,075 patients for whom information about initial Covid illness was available, only 265 had symptoms at that time. They were more likely to be older — their median age was 11, while the median age of those with asymptomatic Covid infections was 8. But that could be because “younger children can’t express their concerns as well,” said Dr. Blumenthal, who co-wrote an editorial about the study.

“We don’t necessarily know if there’s actually less symptomatology in the very young population, ” she said.

Similarly unclear are the reasons behind the study’s finding that in the first wave of MIS-C, from March 1 to July 1, 2020, young people were more prone to a few of the most serious heart complications. Dr. DeBiasi said that did not match the experience of her hospital, where “the kids were sicker in the second wave.”

The study documented two waves of MIS-C cases that followed surges in overall coronavirus cases by about a month or more. “The most recent third peak of the Covid-19 pandemic appears to be leading to another MIS-C peak perhaps involving urban and rural communities,” the authors wrote.

The study found that most of the states where the rate of MIS-C cases per population was highest were in the Northeast, which had the first surge of cases, and the South. By contrast, most states with high per-population rates of children with Covid-19 but low rates of MIS-C were in the Midwest and West. While the concentration of cases spread from large cities to smaller towns over time, it wasn’t as pronounced as the overall pandemic trends, the authors said.

Dr. Blumenthal said that geographic pattern could reflect that the “understanding of the complications of the disease” hadn’t caught up to its prevalence in different regions or that many states with lower rates of MIS-C have less ethnically diverse populations. “It could also be something about Covid itself, although we don’t know that,” she said. “Right now, we don’t know anything about how the variants necessarily affect children.”

The study represented only the strictest criteria for MIS-C, excluding about 350 reported cases that met the C.D.C. definition of the syndrome but had a negative antibody test or primarily involved respiratory symptoms. Dr. DeBiasi said there are also many probable MIS-C cases that are not reported to the C.D.C. because they don’t meet all the official criteria.

“These probable MIS-C kids, in real life that’s a big chunk of kids,” she said. In addition, while the focus so far has been on serious cases, “there’s another whole group of kids that may actually have mild MIS-C.”

If a community has experienced a recent coronavirus surge, then “just because the kid says, ‘I never had Covid or my parents never had it,’ that doesn’t mean the kid in front of you doesn’t have MIS-C,” Dr. DeBiasi said. “If your city has Covid, then get ready.”

Can Vaccinated People Spread the Virus? We Don’t Know, Scientists Say.

Researchers pushed back after the C.D.C. director asserted that vaccinated people “do not carry the virus.”

The Centers for Disease Control and Prevention on Thursday walked back controversial comments made by its director, Dr. Rochelle P. Walensky, suggesting that people who are vaccinated against the coronavirus never become infected or transmit the virus to others.

The assertion called into question the precautions that the agency had urged vaccinated people to take just last month, like wearing masks and gathering only under limited circumstances with unvaccinated people.

“Dr. Walensky spoke broadly during this interview,” an agency spokesman told The Times. “It’s possible that some people who are fully vaccinated could get Covid-19. The evidence isn’t clear whether they can spread the virus to others. We are continuing to evaluate the evidence.”

The agency was responding in part to criticism from scientists who noted that current research was far from sufficient to claim that vaccinated people cannot spread the virus.

The data suggest that “it’s much harder for vaccinated people to get infected, but don’t think for one second that they cannot get infected,” said Paul Duprex, director of the Center for Vaccine Research at the University of Pittsburgh.

In a television interview with MSNBC’s Rachel Maddow, Dr. Walensky referred to data published by the C.D.C. showing that one dose of the Moderna or Pfizer-BioNTech vaccine was 80 percent effective at preventing infection, and two doses were 90 percent effective.

That certainly suggested that transmission from vaccinated people might be unlikely, but Dr. Walensky’s comments hinted that protection was complete. “Our data from the C.D.C. today suggests that vaccinated people do not carry the virus, don’t get sick,” she said. “And that it’s not just in the clinical trials, it’s also in real-world data.”

Dr. Walensky went on to emphasize the importance of continuing to wear masks and maintain precautions, even for vaccinated people. Still, the brief comment was widely interpreted as saying that the vaccines offered complete protection against infection or transmission.

In a pandemic that regularly spawns scientific misunderstanding, experts said they were sympathetic to Dr. Walensky and her obvious desire for Americans to continue to take precautions. It was only Monday that she said rising caseloads had left her with a sense of “impending doom.”

“If Dr. Walensky had said most vaccinated people do not carry virus, we would not be having this discussion,” said John Moore, a virologist at Weill Cornell Medicine in New York.

“What we know is the vaccines are very substantially effective against infection — there’s more and more data on that — but nothing is 100 percent,” he added. “It is an important public health message that needs to be gotten right.”

Misinterpretation could disrupt the agency’s urgent pleas for immunization, some experts said. As of Wednesday, 30 percent of Americans had received at least one dose of a vaccine and 17 percent were fully immunized.

“There cannot be any daylight between what the research shows — really impressive but incomplete protection — and how it is described,” said Dr. Peter Bach, director of the Center for Health Policy and Outcomes at Memorial Sloan Kettering Cancer Center in New York.

“This opens the door to the skeptics who think the government is sugarcoating the science,” Dr. Bach said, “and completely undermines any remaining argument why people should keep wearing masks after being vaccinated.”

All of the coronavirus vaccines are spectacularly successful at preventing serious disease and death from Covid-19, but how well they prevent infection has been less clear.

Clinical trials of the vaccines were designed only to assess whether the vaccines prevent serious illness and death. The research from the C.D.C. on Monday brought the welcome conclusion that the vaccines are also extremely effective at preventing infection.

The study enrolled 3,950 health care workers, emergency responders and others at high risk of infection. The participants swabbed their noses each week and sent the samples in for testing, which allowed federal researchers to track all infections, symptomatic or not. Two weeks after vaccination, the vast majority of vaccinated people remained virus-free, the study found.

Follow-up data from clinical trials support that finding. In results released by Pfizer and BioNTech on Wednesday, for example, 77 people who received the vaccine had a coronavirus infection, compared with 850 people who got a placebo.

“Clearly, some vaccinated people do get infected,” Dr. Duprex said. “We’re stopping symptoms, we’re keeping people out of hospitals. But we’re not making them completely resistant to an infection.”

The number of vaccinated people who become infected is likely to be higher among those receiving vaccines made by Johnson & Johnson and AstraZeneca, which have a lower efficacy, experts said. (Still, those vaccines are worth taking, because they uniformly prevent serious illness and death.)

Infection rates may also be higher among people exposed to a virus variant that can sidestep the immune system.

Cases across the country are once again on the upswing, threatening a new surge. Dr. Walensky’s comment came just a day after she made an emotional appeal to the American public to continue taking precautions.

“I am asking you to just hold on a little longer, to get vaccinated when you can, so that all of those people that we all love will still be here when this pandemic ends,” she said.

Given the rising numbers, it’s especially important that immunized people continue to protect those who have not yet been immunized against the virus, experts said.

“Vaccinated people should not be throwing away their masks at this point,” Dr. Moore said. “This pandemic is not over.”

Coronavirus Reinfections Are Rare, Danish Researchers Report

People over 65 are more likely to experience a second bout with the virus, according to a large study of medical records.

The vast majority of people who recover from Covid-19 remain shielded from the virus for at least six months, researchers reported on Wednesday in a large study from Denmark.

Prior infection with the coronavirus reduced the chances of a second bout by about 80 percent in people under 65, but only by about half in those older than 65. But those results, published in the journal Lancet, were tempered by many caveats.

The number of infected older people in the study was small. The researchers did not have any information beyond the test results, so it’s possible that only people who were mildly ill the first time became infected again and that the second infections were largely symptom-free.

Scientists have said that reinfections are likely to be asymptomatic or mild because the immune system will suppress the virus before it can do much damage. The researchers also did not assess the possibility of reinfection with newer variants of the virus.

Still, the study suggests that immunity to a natural infection is unpredictable and uneven, and it underscores the importance of vaccinating everyone — especially older people, experts said.

“You can certainly not rely on a past infection as protecting you from being ill again, and possibly quite ill if you are in the elderly segment,” said Steen Ethelberg, an epidemiologist at Statens Serum Institut, Denmark’s public health agency.

Because people over 65 are at highest risk of severe disease and death, he said, “they are the ones we are most eager to protect.”

Rigorous estimates of second infections have generally been rare because many people worldwide did not initially have access to testing, and laboratories require genetic sequences from both rounds of testing to confirm a reinfection.

But the findings are consistent with those from experiments in a wide variety of settings: sailors on a fishing trawler in Seattle, Marine Corps recruits in South Carolina, health care workers in Britain and patients at clinics in the United States.

The new study’s design and size benefited from Denmark’s free and abundant testing for the coronavirus. Nearly 70 percent of the country’s population was tested for the virus in 2020.

The researchers looked at the results from 11,068 people who tested positive for the coronavirus during the first wave in Denmark between March and May 2020. During the second wave, from September to December, 72 of those people, or 0.65 percent, again tested positive, compared with 3.27 percent of people who became infected for the first time.

That translates to a 80 percent protection from the virus in those who had been infected before. The protection fell to 47 percent for those over 65. The team also analyzed test results from nearly 2.5 million people throughout the epidemic, some longer than seven months after the first infection, and found similar results.

“It was really nice to see that there was no difference in protection from reinfection over time,” said Marion Pepper, an immunologist at the University of Washington in Seattle.

She and other experts noted that while 80 percent might not seem superb, protection from symptomatic illness was likely to be higher. The analysis included anyone who was tested, regardless of symptoms.

“A lot of these will be asymptomatic infections, and a lot of these will likely be people who have a blip of virus,” noted Florian Krammer, an immunologist at the Icahn School of Medicine at Mount Sinai in New York. “Eighty percent risk reduction against asymptomatic infection is great.”

The findings indicate that people who have recovered from Covid-19 should get at least one dose of a coronavirus vaccine to boost the level of protection, Dr. Krammer added. Most people produce robust immune response to a natural infection, “but there’s a lot of variability,” he said. Following vaccination, “we don’t see variability — we see very high responses in basically everybody, with very few exceptions.”

Experts were less convinced by the results in people over 65, saying the findings would have been more robust if the analysis had included more people from that age group.

“I wish it had actually been broken down into specific decades over 65,” Dr. Pepper said. “It would be nice to know whether the majority of people who were getting reinfected were over 80.”

The immune system grows progressively weaker with age, and people over 80 typically mount weak responses to infection with a virus. The lower protection in older people seen in the study is consistent with those observations, said Akiko Iwasaki, an immunologist at Yale University.

“I think we kind of tend to forget how the vaccines have been pretty amazing in offering protection in this age group, because you can see that natural infection doesn’t confer the same kind of protection,” she said. “This really does emphasize the need to cover older people with the vaccine, even if they have had Covid first.”

Some Long Covid-19 Patients Feel Better After Vaccine Doses

It is too soon to tell whether the shots have a broad beneficial effect on patients with continuing issues, but scientists are intrigued and beginning to study the phenomenon.

Judy Dodd began struggling with long Covid symptoms last spring — shortness of breath, headaches, exhaustion. Then she got the vaccine.

After her first Pfizer-BioNTech shot in late January, she felt so physically miserable that she had to be persuaded to get the second. For three days after that one, she also felt awful. But the fourth day, everything changed.

“I woke up and it was like ‘Oh what a beautiful morning,’” said Ms. Dodd, a middle-school teacher who is also an actor and director. “It was like I’d been directing ‘Sweeney Todd’ for months, and now I’m directing Oklahoma.”

Ms. Dodd, who continues to feel good, is among a number of people who are reporting that the post-Covid symptoms they’ve experienced for months have begun improving, sometimes significantly, after they got the vaccine. It’s a phenomenon that doctors and scientists are watching closely, but as with much about the yearlong coronavirus pandemic, there are many uncertainties.

Scientists are only beginning to study any potential effect of vaccines on long Covid symptoms. Anecdotes run the gamut: Besides those who report feeling better after the shots, many people say they have experienced no change and a small number say they feel worse.

Reports from doctors vary too. Dr. Daniel Griffin, an infectious disease physician at Columbia University, said about 40 percent of the long Covid patients he’s been treating cite symptom improvement after the vaccine. “They notice, ‘Hey, over the days, I’m feeling better. The fatigue isn’t so bad, maybe smell is coming back,’” Dr. Griffin said.

Other doctors say it is too early to know.

“Too few of our participants have been vaccinated so far to really be able to provide insight into this question,” said Dr. Michael Peluso, an infectious disease specialist working on a study of long-term Covid patients at University of California, San Francisco. “I’ve heard anecdotes as well, but I’ve seen too little data so far.”

This month, a small study by British researchers that has not yet been peer reviewed found that eight months after people were hospitalized for Covid-19, those who were vaccinated experienced improvement in more long Covid symptoms than those who weren’t yet vaccinated. The 44 vaccinated patients in the study were older and had more underlying medical conditions, since people with those characteristics qualified for vaccines earlier.

One month after vaccination, those patients reported improvement in 23 percent of their long Covid symptoms like joint pain and breathing, while 5.6 percent of their symptoms had worsened. The 22 unvaccinated people questioned at that time said 15 percent of their symptoms were better, while 14 percent of their symptoms were worse. There was no difference in response between people who received the Pfizer-BioNTech and Oxford-AstraZeneca vaccines.

Additional information comes from two surveys of several hundred people with long Covid symptoms, many of whom were never hospitalized for the disease.

Jim Golen, a former hospice nurse in Saginaw, Minn. He said his long Covid symptoms have gotten worse since his vaccination, but he’s still glad he got the vaccine.
Jim Golen, a former hospice nurse in Saginaw, Minn. He said his long Covid symptoms have gotten worse since his vaccination, but he’s still glad he got the vaccine.Tim Gruber for The New York Times

One survey of 345 people, mostly women and mostly in the U.K., found that two weeks or more after their second vaccine dose, 93 felt slightly better and 18 felt back to normal — a total of 32 percent reporting improved long Covid symptoms.

In that survey, by Gez Medinger, a London-based filmmaker who has experienced post-Covid symptoms, 61 people, just under 18 percent, felt worse, most of them reporting only a slight decline in their condition. Nearly half — 172 people — reported feeling no different.

Another survey, by Survivor Corps, a group of over 150,000 Covid survivors, found that as of March 17, 225 of 577 respondents reported some improvement, while 270 felt no change and 82 felt worse.

Jim Golen, 55, of Saginaw, Minn., feels some long Covid symptoms have worsened since his vaccination. Mr. Golen, a former hospice nurse who also has a small farm, had experienced months of difficulty, including blood clots in his lungs, chest pain, brain fog, insomnia and shortness of breath with any exertion. Late last year, after seeing several doctors, “I was finally starting to get better,” he said.

Since receiving the second dose of the Pfizer vaccine in mid-January, he said, his chest burning and shortness of breath have returned with a vengeance, especially if he taxes himself with activities like collecting sap from the maple trees on his farm. Nonetheless, Mr. Golen said he was “very happy” to be vaccinated, emphasizing that the effects of Covid were worse and preventing it is crucial.

Some people shared stories of stark symptom improvements that took them by surprise.

Laura Gross, 72, of Fort Lee, N.J. rattled off a lengthy list of debilitating long Covid symptoms she’d experienced since April, including exhaustion, joint pain, muscle aches and a “zizzy-dizzy-weaky thing that was like an internal headachy all-over-body vibration.”

Her cognitive fuzziness and forgetfulness were so intense that “brain fog barely describes it,” she said. “It’s more like brain cyclone.”

She also felt uncharacteristically “hopeless, sad, lonely, unmotivated,” she said.

Three days after her first Moderna shot in late January, everything changed. “It was like a revelation,” she said. The brain fog cleared completely, muscle aches were gone, joint pains were less intense and she suddenly had much more energy. It felt, she said, “like the old me.”

That continued after the second dose. “It’s like my cells went kerflooey last year when they met Covid,” she said, and the “vaccine said, ‘Wait, you dopes, that isn’t how you fight this, do it this way.’”

Recently, she walked briskly for 23 minutes and even “ran a little bit because I was so happy,” she said. “I’m a very happy little chappy.”

Laura Gross of Fort Lee, N.J., said brain fog is inadequate in describing her symptoms: “It’s more like brain cyclone,” she said. She reports feeling much better since being vaccinated.Nancy Borowick for The New York Times

Scientists say that understanding whether vaccines help some long Covid patients but not others could help unravel the underlying causes of different symptoms and potential ways to treat them.

“They might be different disease processes and you manage them differently,” said Dr. Adam Lauring, a virologist and infectious disease physician at the University of Michigan. “It might be that there’s a subset of people who have a certain type of long Covid, who respond well to vaccines, but there might be other people who have a different subtype that we haven’t quite defined yet.”

Akiko Iwasaki, an immunologist at Yale, said that a vaccine, by generating antibodies to the coronavirus’s spike protein, could potentially eliminate vestiges of the virus or remnants of viral RNA that may linger in some patients.

If this is occurring, she said, it could suggest that the vaccine “might be like a permanent cure” for those patients.

Dr. Iwasaki said the vaccine might also help people whose long Covid symptoms may be caused by a post-viral response resembling an autoimmune disease if “the vaccine stimulates innate immune responses that dampen these kinds of autoreactive responses,” she said. But based on experiences of people with other autoimmune diseases, that relief would “not be very long-lasting and they would kind of revert back” to having symptoms like fatigue, she said.

Dr. Eric Topol, a professor of molecular medicine at the Scripps Research Institute in San Diego, said he is starting a study to measure physiological information like heart rate, respiratory rate, temperature and markers of immune system response in people with long Covid before they receive a vaccine and weeks afterward.

It’s plausible that “you have your immune system revved up when you’re fighting a reservoir” of virus or RNA remnants, he said, “and that could be an explanation of why you’re in overdrive with your heart rate.” He wants to see if these biological indicators improve post-vaccine.

“We’d really like objective metrics that show that you not just feel better,” Dr. Topol said. “You could feel better from the placebo effect, but it’s unlikely your heart rate’s going to go from 100 to 60 because of a placebo effect. And if we keep seeing that pattern, that would be like Eureka.”

He added, “I think there’s probably something there, but I just don’t know what is the magnitude, how many people are going to benefit.”

There are many other questions: Are there specific characteristics, like age, gender, type or duration of symptoms, that might make some long Covid patients more likely to feel better? Would a vaccine be less effective for people with more complex conditions: people whose symptoms are driven by multiple biological pathways (perhaps both an RNA remnant and autoimmune activation) or whose symptoms have changed or fluctuated over time? Are certain types of vaccines more likely to produce benefit?

“It was awful thinking it may never get better, like ‘Is this my new normal, am I now damaged this way?’” recalled Bridget Hayward of her symptoms, which she says have eased since her vaccination.Alyssa Schukar for The New York Times

Bridget Hayward, 51, an operating room nurse in Alexandria, Va., said that after contracting Covid a year ago, her body ached from her hands to her hips and she became so brain-fogged that instead of asking for a scalpel, she would say “Give me that sharp thing we cut with.”

Almost daily, she would briefly pass out while bending down to fix a patient’s intravenous line or plug in the cord of a hospital bed.

“It was horrifying,” she said. “It was awful thinking it may never get better, like ‘Is this my new normal, am I now damaged this way?’”

After several months, her worst symptoms improved, but she still tired easily, felt hot even in cool weather, and found it too taxing to do some ordinary tasks, she said.

One day after her first dose of the Pfizer vaccine in late December, “it was like click, everything is fine,” she said. Her body temperature has normalized and “it felt like a darkness lifted.”

While “it’s not 100 percent every day,” she said she has so much energy now that “I’m not just getting from A to B, I’m like leaping up.”

One recent day, she did several long-overdue errands. “This may not sound like much but it is a 180-turnaround from three months ago,” she said. “I’m back!”

Kim Leighton, 64, of Vancouver, Wash., has had a similar experience. She was hospitalized last March and had long Covid symptoms that included mini blackouts, shortness of breath, getting lost in her own neighborhood, depression and fatigue.

“It really has been hell,” she said.

When she started feeling better in late January, she didn’t even think to connect it to the vaccine, but later realized her stark improvement had started four days after receiving her first Moderna shot. She is delighted that she can now take walks in downtown Portland and has the desire to reconnect with friends.

“Every day, I feel like I’m feeling stronger,” Ms. Leighton said. “All the stuff I had to let go of, I’m trying to get it back.”

Ms. Dodd, like several others, said she wasn’t taking her improvement for granted. “I’m still sort of wary of what’s around the corner, this disease is so unpredictable,” she said.

But, she added, “even if, God forbid, I have a relapse, to have this time now when I feel better, it’s really amazing.”

Some Long Covid Patients Feel Better After Getting the Vaccine

It is too soon to tell whether the shots have a broad beneficial effect on patients with continuing issues, but scientists are intrigued and beginning to study the phenomenon.

Judy Dodd began struggling with long Covid symptoms last spring — shortness of breath, headaches, exhaustion. Then she got the vaccine.

After her first Pfizer-BioNTech shot in late January, she felt so physically miserable that she had to be persuaded to get the second. For three days after that one, she also felt awful. But the fourth day, everything changed.

“I woke up and it was like ‘Oh what a beautiful morning,’” said Ms. Dodd, a middle-school teacher who is also an actor and director. “It was like I’d been directing ‘Sweeney Todd’ for months, and now I’m directing Oklahoma.”

Ms. Dodd, who continues to feel good, is among a number of people who are reporting that the post-Covid symptoms they’ve experienced for months have begun improving, sometimes significantly, after they got the vaccine. It’s a phenomenon that doctors and scientists are watching closely, but as with much about the yearlong coronavirus pandemic, there are many uncertainties.

Scientists are only beginning to study any potential effect of vaccines on long Covid symptoms. Anecdotes run the gamut: Besides those who report feeling better after the shots, many people say they have experienced no change and a small number say they feel worse.

Reports from doctors vary too. Dr. Daniel Griffin, an infectious disease physician at Columbia University, said about 40 percent of the long Covid patients he’s been treating cite symptom improvement after the vaccine. “They notice, ‘Hey, over the days, I’m feeling better. The fatigue isn’t so bad, maybe smell is coming back,’” Dr. Griffin said.

Other doctors say it is too early to know.

“Too few of our participants have been vaccinated so far to really be able to provide insight into this question,” said Dr. Michael Peluso, an infectious disease specialist working on a study of long-term Covid patients at University of California, San Francisco. “I’ve heard anecdotes as well, but I’ve seen too little data so far.”

This month, a small study by British researchers that has not yet been peer reviewed found that eight months after people were hospitalized for Covid-19, those who were vaccinated experienced improvement in more long Covid symptoms than those who weren’t yet vaccinated. The 44 vaccinated patients in the study were older and had more underlying medical conditions, since people with those characteristics qualified for vaccines earlier.

One month after vaccination, those patients reported improvement in 23 percent of their long Covid symptoms like joint pain and breathing, while 5.6 percent of their symptoms had worsened. The 22 unvaccinated people questioned at that time said 15 percent of their symptoms were better, while 14 percent of their symptoms were worse. There was no difference in response between people who received the Pfizer-BioNTech and Oxford-AstraZeneca vaccines.

Additional information comes from two surveys of several hundred people with long Covid symptoms, many of whom were never hospitalized for the disease.

Jim Golen, a former hospice nurse in Saginaw, Minn. He said his long Covid symptoms have gotten worse since his vaccination, but he’s still glad he got the vaccine.
Jim Golen, a former hospice nurse in Saginaw, Minn. He said his long Covid symptoms have gotten worse since his vaccination, but he’s still glad he got the vaccine.Tim Gruber for The New York Times

One survey of 345 people, mostly women and mostly in the U.K., found that two weeks or more after their second vaccine dose, 93 felt slightly better and 18 felt back to normal — a total of 32 percent reporting improved long Covid symptoms.

In that survey, by Gez Medinger, a London-based filmmaker who has experienced post-Covid symptoms, 61 people, just under 18 percent, felt worse, most of them reporting only a slight decline in their condition. Nearly half — 172 people — reported feeling no different.

Another survey, by Survivor Corps, a group of over 150,000 Covid survivors, found that as of March 16, 207 of 508 respondents reported some improvement, while 231 felt no change and 70 felt worse.

Jim Golen, 55, of Saginaw, Minn., feels some long Covid symptoms have worsened since his vaccination. Mr. Golen, a former hospice nurse who also has a small farm, had experienced months of difficulty, including blood clots in his lungs, chest pain, brain fog, insomnia and shortness of breath with any exertion. Late last year, after seeing several doctors, “I was finally starting to get better,” he said.

Since receiving the second dose of the Pfizer vaccine in mid-January, he said, his chest burning and shortness of breath have returned with a vengeance, especially if he taxes himself with activities like collecting sap from the maple trees on his farm. Nonetheless, Mr. Golen said he was “very happy” to be vaccinated, emphasizing that the effects of Covid were worse and preventing it is crucial.

Some people shared stories of stark symptom improvements that took them by surprise.

Laura Gross, 72, of Fort Lee, N.J. rattled off a lengthy list of debilitating long Covid symptoms she’d experienced since April, including exhaustion, joint pain, muscle aches and a “zizzy-dizzy-weaky thing that was like an internal headachy all-over-body vibration.”

Her cognitive fuzziness and forgetfulness were so intense that “brain fog barely describes it,” she said. “It’s more like brain cyclone.”

She also felt uncharacteristically “hopeless, sad, lonely, unmotivated,” she said.

Three days after her first Moderna shot in late January, everything changed. “It was like a revelation,” she said. The brain fog cleared completely, muscle aches were gone, joint pains were less intense and she suddenly had much more energy. It felt, she said, “like the old me.”

That continued after the second dose. “It’s like my cells went kerflooey last year when they met Covid,” she said, and the “vaccine said, ‘Wait, you dopes, that isn’t how you fight this, do it this way.’”

Recently, she walked briskly for 23 minutes and even “ran a little bit because I was so happy,” she said. “I’m a very happy little chappy.”

Laura Gross of Fort Lee, N.J., said brain fog is inadequate in describing her symptoms: “It’s more like brain cyclone,” she said. She reports feeling much better since being vaccinated.Nancy Borowick for The New York Times

Scientists say that understanding whether vaccines help some long Covid patients but not others could help unravel the underlying causes of different symptoms and potential ways to treat them.

“They might be different disease processes and you manage them differently,” said Dr. Adam Lauring, a virologist and infectious disease physician at the University of Michigan. “It might be that there’s a subset of people who have a certain type of long Covid, who respond well to vaccines, but there might be other people who have a different subtype that we haven’t quite defined yet.”

Akiko Iwasaki, an immunologist at Yale, said that a vaccine, by generating antibodies to the coronavirus’s spike protein, could potentially eliminate vestiges of the virus or remnants of viral RNA that may linger in some patients.

If this is occurring, she said, it could suggest that the vaccine “might be like a permanent cure” for those patients.

Dr. Iwasaki said the vaccine might also help people whose long Covid symptoms may be caused by a post-viral response resembling an autoimmune disease if “the vaccine stimulates innate immune responses that dampen these kinds of autoreactive responses,” she said. But based on experiences of people with other autoimmune diseases, that relief would “not be very long-lasting and they would kind of revert back” to having symptoms like fatigue, she said.

Dr. Eric Topol, a professor of molecular medicine at the Scripps Research Institute in San Diego, said he is starting a study to measure physiological information like heart rate, respiratory rate, temperature and markers of immune system response in people with long Covid before they receive a vaccine and weeks afterward.

It’s plausible that “you have your immune system revved up when you’re fighting a reservoir” of virus or RNA remnants, he said, “and that could be an explanation of why you’re in overdrive with your heart rate.” He wants to see if these biological indicators improve post-vaccine.

“We’d really like objective metrics that show that you not just feel better,” Dr. Topol said. “You could feel better from the placebo effect, but it’s unlikely your heart rate’s going to go from 100 to 60 because of a placebo effect. And if we keep seeing that pattern, that would be like Eureka.”

He added, “I think there’s probably something there, but I just don’t know what is the magnitude, how many people are going to benefit.”

There are many other questions: Are there specific characteristics, like age, gender, type or duration of symptoms, that might make some long Covid patients more likely to feel better? Would a vaccine be less effective for people with more complex conditions: people whose symptoms are driven by multiple biological pathways (perhaps both an RNA remnant and autoimmune activation) or whose symptoms have changed or fluctuated over time? Are certain types of vaccines more likely to produce benefit?

“It was awful thinking it may never get better, like ‘Is this my new normal, am I now damaged this way?’” recalled Bridget Hayward of her symptoms, which she says have eased since her vaccination.Alyssa Schukar for The New York Times

Bridget Hayward, 51, an operating room nurse in Alexandria, Va., said that after contracting Covid a year ago, her body ached from her hands to her hips and she became so brain-fogged that instead of asking for a scalpel, she would say “Give me that sharp thing we cut with.”

Almost daily, she would briefly pass out while bending down to fix a patient’s intravenous line or plug in the cord of a hospital bed.

“It was horrifying,” she said. “It was awful thinking it may never get better, like ‘Is this my new normal, am I now damaged this way?’”

After several months, her worst symptoms improved, but she still tired easily, felt hot even in cool weather, and found it too taxing to do some ordinary tasks, she said.

One day after her first dose of the Pfizer vaccine in late December, “it was like click, everything is fine,” she said. Her body temperature has normalized and “it felt like a darkness lifted.”

While “it’s not 100 percent every day,” she said she has so much energy now that “I’m not just getting from A to B, I’m like leaping up.”

One recent day, she did several long-overdue errands. “This may not sound like much but it is a 180-turnaround from three months ago,” she said. “I’m back!”

Kim Leighton, 64, of Vancouver, Wash., has had a similar experience. She was hospitalized last March and had long Covid symptoms that included mini blackouts, shortness of breath, getting lost in her own neighborhood, depression and fatigue.

“It really has been hell,” she said.

When she started feeling better in late January, she didn’t even think to connect it to the vaccine, but later realized her stark improvement had started four days after receiving her first Moderna shot. She is delighted that she can now take walks in downtown Portland and has the desire to reconnect with friends.

“Every day, I feel like I’m feeling stronger,” Ms. Leighton said. “All the stuff I had to let go of, I’m trying to get it back.”

Ms. Dodd, like several others, said she wasn’t taking her improvement for granted. “I’m still sort of wary of what’s around the corner, this disease is so unpredictable,” she said.

But, she added, “even if, God forbid, I have a relapse, to have this time now when I feel better, it’s really amazing.”

Moderna Starts Testing Its Covid Vaccine in Babies and Young Children

The company will study its vaccine in children ages six months through 11 in the United States and Canada.

The drug company Moderna has begun a study that will test its Covid vaccine in children under 12, including babies as young as six months, the company said on Tuesday.

The study is expected to enroll 6,750 healthy children in the United States and Canada. Moderna declined to say how many had already signed up or received the first shots, according to a spokeswoman, Colleen Hussey.

“There’s a huge demand to find out about vaccinating kids and what it does,” said Dr. David Wohl, the medical director of the vaccine clinic at the University of North Carolina, who is not involved the study.

In a separate study, Moderna is testing its vaccine in 3,000 children ages 12 to 17, and may have results for that age group by summer. The vaccine would then have to be authorized for use in children, so it would not be immediately available.

Many parents want protection for their children, and vaccinating children should help to produce the herd immunity considered crucial to stopping the pandemic. The American Academy of Pediatrics has called for expansion of vaccine trials to include children.

Vaccine side effects like fever, sore arms, fatigue and achy joints and muscles can be more intense in children than in adults, and doctors say it is important for parents to know what to expect after their children are inoculated.

Each child in Moderna’s study will receive two shots, 28 days apart. The study will have two parts. In the first, children aged 2 years to less than 12 may receive two doses of 50 or 100 micrograms each. Those under 2 years may receive two shots of 25, 50 or 100 micrograms.

In each group, the first children inoculated will receive the lowest doses and will be monitored for reactions before later participants are given higher doses.

Then, researchers will perform an interim analysis to determine which dose is safest and most likely to be protective for each age group.

Children in part 2 of the study will receive the doses selected by the analysis — or placebo shots consisting of salt water.

Moderna developed its vaccine in collaboration with the National Institute of Allergy and Infectious Diseases. The company and the institute are also working together on the study, along with the federal Biomedical Advanced Research and Development Authority.

The children will be followed for a year, to look for side effects and measure antibody levels that will help researchers determine whether the vaccine appears to provide protection. The antibody levels will be the main indicator, but the researchers will also look for coronavirus infections, with or without symptoms.

Dr. Wohl said the study appeared well designed and likely to be efficient, but he questioned why the children were to be followed for only one year, when adults in Moderna’s study are followed for two years. He also said he was somewhat surprised to see the vaccine being tested in children so young this soon.

“Should we learn first what happens in the older kids before we go to the really young kids?” Dr. Wohl asked. Most young children do not become very ill from Covid, he said, though some develop a severe inflammatory syndrome that can be life threatening.

Johnson & Johnson has also said it would test its coronavirus vaccine in babies and young children after testing it first in older children.

Pfizer-BioNTech is testing its vaccine in children ages 12 to 15, and has said it plans to move to younger groups; the product is already authorized for use in those 16 and up in the United States.

Last month, AstraZeneca began testing its vaccine in Britain in children 6 years and older.

Plan to Ditch the Mask After Vaccination? Not So Fast.

Plan to Ditch the Mask After Vaccination? Not So Fast.

It’s not clear how easily vaccinated people may spread the virus, but the answer to that question is coming soon. Until then, scientists urge caution.

A health care worker prepared a dose of the Pfizer-BioNTech vaccine at a vaccination site in San Francisco on Monday.
A health care worker prepared a dose of the Pfizer-BioNTech vaccine at a vaccination site in San Francisco on Monday.Credit…Mike Kai Chen for The New York Times
Apoorva Mandavilli

  • March 3, 2021, 3:23 p.m. ET

With 50 million Americans immunized against the coronavirus, and millions more joining the ranks every day, the urgent question on many minds is: When can I throw away my mask?

It’s a deeper question than it seems — about a return to normalcy, about how soon vaccinated Americans can hug loved ones, get together with friends, and go to concerts, shopping malls and restaurants without feeling threatened by the coronavirus.

Certainly many state officials are ready. On Tuesday, Texas lifted its mask mandate, along with all restrictions on businesses, and Mississippi quickly followed suit. Governors in both states cited declining infection rates and rising numbers of citizens getting vaccinated.

But the pandemic is not yet over, and scientists are counseling patience.

It seems clear that small groups of vaccinated people can get together without much worry about infecting one another. The Centers for Disease Control and Prevention is expected shortly to issue new guidelines that will touch on small gatherings of vaccinated Americans.

But when vaccinated people can ditch the masks in public spaces will depend on how quickly the rates of disease drop and what percentage of people remain unvaccinated in the surrounding community.

Why? Scientists do not know whether vaccinated people spread the virus to those who are unvaccinated. While all of the Covid-19 vaccines are spectacularly good at shielding people from severe illness and death, the research is unclear on exactly how well they stop the virus from taking root in an immunized person’s nose and then spreading to others.

It’s not uncommon for a vaccine to forestall severe disease but not infection. Inoculations against the flu, rotavirus, polio and pertussis are all imperfect in this way.

The coronavirus vaccines “are under a lot more scrutiny than any of the previous vaccines ever have been,” said Neeltje van Doremalen, an expert in preclinical vaccine development at the National Institutes of Health’s Rocky Mountain Laboratories in Montana.

And now coronavirus variants that dodge the immune system are changing the calculus. Some vaccines are less effective at preventing infections with certain variants, and in theory could allow more virus to spread.

The research available so far on how well the vaccines prevent transmission is preliminary but promising. “We feel confident that there’s a reduction,” said Natalie Dean, a biostatistician at the University of Florida. “We don’t know the exact magnitude, but it’s not 100 percent.”

Still, even an 80 percent drop in transmissibility might be enough for immunized people to toss their masks, experts said — especially once a majority of the population is inoculated, and as rates of cases, hospitalizations and deaths plummet.

A line to register for a vaccination appointment in San Francisco. Experts say that people who have been inoculated should continue to wear masks to protect others.
A line to register for a vaccination appointment in San Francisco. Experts say that people who have been inoculated should continue to wear masks to protect others.Credit…Mike Kai Chen for The New York Times

But most Americans are still unvaccinated, and more than 1,500 people are dying every day. So given the uncertainty around transmission, even people who are immunized must continue to protect others by wearing masks, experts said.

“They should wear masks until we actually prove that vaccines prevent transmission,” said Dr. Anthony S. Fauci, director of the National Institute for Allergy and Infectious Diseases.

That proof is not yet in hand because the clinical trials for vaccines were designed to test whether the vaccines prevent serious illness and death, which usually reflects the virus’s impact on the lungs. Transmission, on the other hand, is driven by its growth in the nose and throat.

Primed by the vaccine, the body’s immune fighters should curb the virus soon after infection, shortening the infection period and curtailing the amounts in the nose and throat. That ought to significantly reduce the chances that a vaccinated person might infect others.

Animal studies support the theory. In one study, when monkeys were immunized and then exposed to the virus, seven of eight animals had no detectable virus in their noses or lung fluid, noted Juliet Morrison, a virologist at the University of California, Riverside.

Similarly, data from a few dozen participants in the Moderna trial who were tested when they got their second doses suggested that the first dose had decreased cases of infection by about two-thirds.

Another small batch of data emerged recently from the Johnson & Johnson trial. Researchers looked for signs of infection in 3,000 participants up to 71 days after getting the single-dose vaccine. Risk of infection in that study seemed to fall by about 74 percent.

“I think that’s very powerful,” said Dan Barouch, a virologist at Beth Israel Medical Center in Boston, who led one of the trial sites. “Those number estimates could change with more data, but the effect seems quite strong.”

More data is expected in the coming months from both Pfizer-BioNTech and Moderna.

But clinical trials may overestimate the power of a vaccine, because the type of people who choose to participate already tend to be careful and are counseled on precautions during the trial.

Some researchers instead are tracking infections among immunized people in real-world settings. For example, a study in Scotland conducted tests every two weeks, regardless of symptoms, on health care workers who had received the Pfizer-BioNTech vaccine. Investigators found that the vaccine’s effectiveness in preventing infection was 70 percent after one dose, and 85 percent after the second.

Researchers in Israel assessed infections in almost 600,000 immunized people and tried to trace their household contacts. The scientists found a 46 percent drop in infections after the first dose and a 92 percent drop after the second. (The study may have missed infections in people without symptoms.)

But to get a true assessment of transmission, researchers really need to know which immunized people become infected, and then trace the spread of the virus among their contacts with genetic analysis.

“That’s the ideal way to actually do this,” said Dr. Larry Corey, an expert in vaccine development at The Fred Hutchinson Cancer Research Center in Seattle. He is hoping to conduct such a study in college-age students.

Preparing swab samples at a testing site in San Francisco on Tuesday.Credit…Mike Kai Chen for The New York Times

But what precautions should immunized people take until the results from such studies become available? At the moment, many experts believe that what’s permissible will depend to a large extent on the number of cases in the surrounding community.

The higher the number of cases, the greater the likelihood of transmission — and the more effective vaccines must be in order to stop the spread.

“If the case numbers are zero, it doesn’t matter whether it’s 70 percent or 100 percent,” said Zoe McLaren, a health policy expert at the University of Maryland, referring to vaccine effectiveness.

Mask-wearing policies also will depend on how many unvaccinated people remain in the population. Americans may need to remain cautious as long as vaccination rates are low. But people will be able to relax a bit as those rates rise, and begin to return to normalcy once the virus runs out of others to infect.

“A lot of people have in mind that masks are the first thing that you let up on,” Dr. MacLaren said. In fact, she said, masks provide more freedom by allowing people to go to concerts, travel on buses or airplanes, or go shopping even with unvaccinated people around.

Ultimately, masks are a form of civic responsibility, said Sabra Klein, an immunologist at the Johns Hopkins Bloomberg School of Public Health.

“Are you wearing a mask to protect yourself from severe Covid, or are you wearing a mask for public health?” Dr. Klein said. “It’s right to do your part in the community beyond yourself.”

High Turnover at Nursing Homes Threatens Residents' Care

High Staff Turnover at U.S. Nursing Homes Poses Risks for Residents’ Care

A new study highlights the persistent problems caused by an unstable work force, an underlying threat that may have led to staggering death tolls in the pandemic.

Emergency medical technicians transported a patient from a nursing home to an emergency room bed at St. Joseph’s Hospital in Yonkers, N.Y., last year.
Emergency medical technicians transported a patient from a nursing home to an emergency room bed at St. Joseph’s Hospital in Yonkers, N.Y., last year.Credit…John Minchillo/Associated Press
Reed Abelson

  • March 1, 2021, 4:05 p.m. ET

Extraordinarily high turnover among staffs at nursing homes likely contributed to the shocking number of deaths at the facilities during the pandemic, the authors of a new study suggested.

The study, which was published Monday in Health Affairs, a health policy journal, represents a comprehensive look at the turnover rates in 15,645 nursing homes across the country, accounting for nearly all of the facilities certified by the federal government. The researchers found the average annual rate was 128 percent, with some facilities experiencing turnover that exceeded 300 percent.

“It was really staggering,” said David Grabowski, a professor of health care policy at Harvard Medical School and one of the study’s authors. Researchers pointed to the findings to urge Medicare to publish the turnover rates at individual nursing home sites, as a way of putting a spotlight on substandard conditions and pressuring owners to make improvements.

Inadequate staffing — and low pay — have long plagued nursing homes and quality-of-care for the more than one million residents who live in these facilities. But the pandemic has exposed these issues even more sharply, with investigations underway into some states’ oversight of the facilities as Covid cases spiraled unchecked and deaths skyrocketed.

The high turnover rate likely made it harder for nursing homes to put in place strong infection controls during the pandemic, and led to rampant spread of the coronavirus, said Ashvin Ghandi, the lead author and a health economist and assistant professor at the University of California Los Angeles Anderson School of Management.

Nursing-home owners blame inadequate reimbursement from Medicaid, the federal-state program for elderly skilled nursing care.

“Workforce recruitment and retention is among the most pressing challenges confronting longterm care providers, and we have been calling for help for years,” Dr. David Gifford, the chief medical officer for the American Health Care Association and National Center for Assisted Living, a trade group, said in an emailed statement.

“It’s high past time that providers receive the proper resources to invest in our frontline caregivers in order to improve quality care,” he said.

At least 172,000 deaths from the virus had been reported among either residents or employees of nursing homes and other long-term care facilities by late February, according to a database compiled by The New York Times. The nursing home death toll alone has accounted for more than one-third of all Covid deaths in the United States, although death and case rates have begun to decline steeply as more than 70 percent of residents have received vaccinations.

Eleanor Garrison, a resident of Arbor Springs Health and Rehabilitation Center in Opelika, Ala., last month.
Eleanor Garrison, a resident of Arbor Springs Health and Rehabilitation Center in Opelika, Ala., last month.Credit…Julie Bennett/Associated Press

Industry criticism has also focused on decades of ownership of nursing homes by private equity and other private investment firms, which prioritized profits for investors above the well-being of residents. These owners have long been accused of insufficiently staffing their facilities and underpaying workers.

Labor is one of the main expenses in the operation of a nursing home, Dr. Gandhi said. “It’s not a very high margin industry, in general,” he said. “Any facility trying to maximize profits is going to be thinking carefully about its staffing costs.”

Nursing home staffs have also shown resistance to getting vaccinated against the coronavirus, complicating efforts by public health officials and nursing homes to provide blanket immunization protection for an individual facility. If a nurse who was immunized leaves and is replaced, the facility will need to ensure the new employee is also vaccinated, especially given the reluctance of some workers to getting a coronavirus shot.

“Trying to do a one-shot vaccination push isn’t enough,” Dr. Gandhi said. “You need continued vaccination outreach.”

Registered nurses, who are the most skilled workers, had the highest rates of turnover, and turnover varied widely across facilities. Among the states with the highest rates were Oklahoma, Montana and Kansas. Facilities that had low-star ratings on Medicare’s website comparing nursing homes had the highest median turnover, and nursing homes with high ratings had the lowest turnover. Turnover was also higher at for-profit institutions, owned by chains and those serving Medicaid beneficiaries, according to the study.

Melissa Unger, the executive director at S.E.I.U. 503, an Oregon division of the Service Employees International Union, said nurses struggle to work at facilities with too few staff members to adequately care for the residents.

“You don’t feel great about the job you’re doing,” Ms. Unger said, noting that many staff members are women and people of color. “You’re doing all of that for crappy benefits and low pay.”

Summer Trosko, a union member working at an Oregon nursing home, said she was used to colleagues leaving from burnout because of inadequate staffing and a lack of money. “They get tired and just can’t take it anymore and quit,” she said. Many are replaced by people who have just graduated from high school with little training, she said.

In addition to making the turnover rates available to the public, the authors point to a number of steps lawmakers could take to improve retention. Medicare could incorporate turnover into its star-rating system, and Medicare and Medicaid could reward nursing homes with higher rates if they had lower turnover. “If we’re going to change nursing homes, we have to start with the staff,” Dr. Grabowski said.

The researchers used newly available payroll-based data collected by the Centers for Medicare and Medicaid Services for registered nurses, licensed practical nurses and certified nursing assistants to calculate turnover rates in 2017 and 2018. They looked at the percentage of hours worked by a nursing employee in a given year and calculated higher rates if the person leaving had provided more care.

¿Hay alimentos adictivos?

La comida muy procesada no solo es dañina, también podría ser adictiva

Los investigadores intentan saber si son adictivos los alimentos ultraprocesados, como las papas fritas o el helado, y si hacen que nuestro cerebro envíe la señal de que comamos en exceso.

Credit…Richard A. Chance
Anahad O’Connor

  • 27 de febrero de 2021 a las 05:00 ET

Hace cinco años, un grupo de científicos especializados en nutrición estudiaron lo que comían los estadounidenses y llegaron a conclusiones sorprendentes: más de la mitad de todas las calorías que consume el estadounidense promedio procede de alimentos ultraprocesados, los cuales definen como “fórmulas industriales” que combinan grandes cantidades de azúcar, sal, aceites, grasas y otros aditivos.

Pese a que se les asocia con la obesidad, las cardiopatías, la diabetes tipo 2 y otros problemas de salud, los alimentos altamente procesados siguen siendo predominantes en la dieta de los estadounidenses. Son baratos, prácticos y están diseñados para que sepan bien. La industria de los alimentos los comercializa de manera entusiasta. Pero una cantidad cada vez mayor de científicos afirma que otra razón por la que estos alimentos se consumen tanto es porque para muchas personas no solo son apetecibles, sino adictivos, una idea que ha provocado controversia entre los investigadores.

Recientemente, la revista American Journal of Clinical Nutrition analizó la ciencia detrás de la adicción alimentaria y si los alimentos ultraprocesados podrían estar contribuyendo a comer en exceso y a la obesidad. Destacó un debate entre dos de los principales expertos en el tema, Ashley Geardhardt, profesora adjunta en el Departamento de Psicología de la Universidad de Míchigan, y Johannes Hebebrand, director del Departamento de Psiquiatría, Psicosomática y Psicoterapia para Niños y Adolescentes de la Universidad de Duisburgo-Essen, en Alemania.

Gearhardt, psicóloga clínica, ayudó a desarrollar la Escala de Adicción a los Alimentos de la Universidad de Yale, que es un estudio que se emplea para determinar si una persona muestra indicios de comportamiento adictivo hacia la comida. En un estudio en el que participaron más de 500 personas, ella y sus colegas descubrieron que ciertos alimentos tenían una especial propensión a provocar comportamientos relacionados con la alimentación “parecidos a los de las adicciones”, como compulsión intensa, pérdida del control e incapacidad de reducir su consumo a pesar de experimentar consecuencias perjudiciales y muchas ganas de dejar de comerlos.

Al principio de la lista estaba la pizza, el chocolate, las galletas, el helado, todo tipo de papas fritas y las hamburguesas con queso. Geardhardt ha descubierto en su investigación que estos alimentos tan procesados tienen mucho en común con las sustancias adictivas. Al igual que los cigarrillos y la cocaína, sus ingredientes se derivan de plantas presentes en la naturaleza y de alimentos a los que se les retiran los componentes que ralentizan su absorción, como la fibra, el agua y la proteína. Posteriormente, sus ingredientes más atractivos se refinan y procesan para crear productos que se absorben con rapidez dentro del torrente sanguíneo, lo cual aumenta su capacidad para activar las regiones del cerebro que regulan la sensación de gratificación, las emociones y la motivación.

Gearhardt señaló que la sal, los espesantes, los sabores artificiales y otros aditivos de los alimentos muy procesados refuerzan su seducción al mejorar algunas propiedades como la textura y la sensación que produce en la boca, lo cual se asemeja a la manera en que los cigarrillos contienen una serie de aditivos diseñados para aumentar su potencial adictivo. Por ejemplo, el mentol ayuda a enmascarar el sabor amargo de la nicotina, mientras que otro ingrediente usado en algunos cigarrillos, el cacao, dilata las vías aéreas y aumenta la absorción de la nicotina.

Según Geardhardt, un común denominador de los alimentos ultraprocesados más irresistibles es que contienen grandes cantidades de grasa y carbohidratos refinados, una combinación poderosa que pocas veces se encuentra en los alimentos de origen natural que el ser humano ha evolucionado para consumir, como frutas, vegetales, carne, nueces, miel, frijoles y semillas. Muchos alimentos que encontramos en la naturaleza son ricos en grasas o carbohidratos, pero por lo general no son altos en las dos cosas.

“Las personas no presentan una respuesta conductual adictiva a los alimentos naturales que son buenos para la salud, como las fresas”, afirmó Gearhardt, quien también es directora del Laboratorio de Ciencia de la Alimentación y la Adicción y su Tratamiento en Míchigan. “El subconjunto de alimentos muy procesados está diseñado de un modo muy parecido a cómo producimos otras sustancias adictivas. Estos son los alimentos que pueden ocasionar la pérdida de control y los comportamientos compulsivos y problemáticos que se asemejan a lo que observamos con el alcohol y los cigarrillos”.

En un estudio, Gearhardt descubrió que cuando las personas reducían el consumo de alimentos muy procesados, experimentaban síntomas parecidos a la abstinencia que se observa en los drogadictos, como irritabilidad, fatiga, tristeza y compulsión. En estudios de imágenes del cerebro, otros investigadores han descubierto que las personas que a menudo consumen comida chatarra, con el tiempo pueden desarrollar tolerancia a ella, lo que hace que cada vez requieran mayores cantidades para obtener la misma satisfacción.

En su práctica clínica, Gearhardt ha visto pacientes —algunos obesos y otros no— que luchan en vano para controlar su ingesta de alimentos muy procesados. Algunos intentan comerlos con moderación, pero solo terminan perdiendo el control y comen hasta el punto de vomitar y sentirse angustiados. Muchos de sus pacientes ven que no pueden dejar estos alimentos pese a que tienen dificultades para controlar su diabetes y presentan un aumento excesivo de peso y otros problemas de salud.

“Lo sorprendente es que mis clientes son casi siempre muy conscientes de las consecuencias negativas de su consumo de alimentos altamente procesados, y normalmente han probado docenas de estrategias como dietas de choque y limpiezas para intentar controlar su relación con estos alimentos”, dijo. “Aunque estos intentos pueden funcionar durante un corto periodo de tiempo, casi siempre acaban recayendo”.

Sin embargo, Hebebrand rebate la idea de que algún alimento provoque adicción. Aunque las papas fritas y la pizza pueden parecer irresistibles para algunas personas, él sostiene que no ocasionan un estado mental alterado, lo que es característico de las sustancias adictivas. Por ejemplo, señaló, fumar un cigarrillo, beber una copa de vino o recibir una dosis de heroína provocan una sensación inmediata en el cerebro que los alimentos no producen.

“Siempre sucede que con cualquier droga adictiva casi toda la gente experimenta un estado mental alterado después de consumirla”, señaló Hebebrand. “Eso indica que la sustancia está causando un efecto en nuestro sistema nervioso central. Pero todos ingerimos alimentos muy procesados y nadie siente este estado mental alterado porque la sustancia no llega directamente al cerebro”.

En los trastornos por consumo de sustancias, las personas se vuelven dependientes de una sustancia química específica que actúa en el cerebro, como la nicotina de los cigarrillos o el etanol del vino y el licor. Al principio buscan esta sustancia química para obtener un subidón, y luego se vuelven dependientes de ella para aliviar las emociones negativas y depresivas. Pero en los alimentos altamente procesados no hay ningún compuesto que pueda señalarse como adictivo, dijo Hebebrand. De hecho, la evidencia sugiere que las personas obesas que comen en exceso tienden a consumir una amplia gama de alimentos con diferentes texturas, sabores y composiciones. Hebebrand argumentó que comer en exceso se debe, en parte, a que la industria de alimentos comercializa más de 20.000 productos nuevos cada año, lo que da a la gente acceso a una variedad aparentemente interminable de comidas y bebidas.

“Es la diversidad de alimentos la que resulta tan atractiva y causa el problema, no una sola sustancia en estas comidas”, añadió.

Quienes argumentan en contra de la idea de la adicción a los alimentos también señalan que la mayoría de las personas consumen diariamente alimentos altamente procesados sin mostrar ningún signo de adicción. Pero Gearhardt señala que las sustancias adictivas no enganchan a todos los que las consumen. Según las investigaciones, alrededor de dos tercios de las personas que fuman cigarrillos acaban convirtiéndose en adictos, mientras que un tercio no lo hace. Solo un 21 por ciento de las personas que consumen cocaína a lo largo de su vida se convierten en adictos, mientras que solo un 23 por ciento de las personas que beben alcohol desarrollan una dependencia de este. Los estudios sugieren que hay una amplia gama de factores que determinan que las personas se vuelvan adictas, como su genética, sus antecedentes familiares, su exposición a traumas y sus antecedentes ambientales y socioeconómicos.

“La mayoría de la gente prueba sustancias adictivas y no se vuelve adicta”, dijo Gearhardt. “Así que si estos alimentos son adictivos, no esperaríamos que toda la sociedad se convirtiese en adicta a ellos”.

A las personas que tienen problemas para restringir su ingesta de alimentos muy procesados, Gearhardt les recomienda llevar un registro de todo lo que comen para poder identificar los alimentos que ejercen una mayor atracción, es decir, los que producen una fuerte compulsión y que no se pueden dejar de comer una vez que se inicia el consumo. No se debe tener esos alimentos en casa y, en cambio, es recomendable llenar el refrigerador y la despensa con otras alternativas que les gusten y sean más saludables, señaló.

Se recomienda llevar un registro de los factores desencadenantes que provocan antojos y atracones. Pueden ser emociones como el estrés, el aburrimiento o la soledad. O puede ser el Dunkin’ Donuts por el que pasas en carro tres veces a la semana. Elabora un plan para controlar esos factores desencadenantes como, por ejemplo, tomar una ruta diferente para volver a casa o realizar actividades no alimentarias para aliviar el estrés y el aburrimiento. Y evita saltarte las comidas, porque el hambre puede desencadenar antojos que conduzcan a decisiones lamentables, dijo.

“Con el fin de poder transitar mejor un entorno alimentario muy desafiante, es importante asegurarte de proporcionarle a tu cuerpo alimentos nutritivos y muy poco procesados que te gusten con regularidad”, comentó Gearhardt.

Anahad O’Connor cubre temas de salud, ciencia, nutrición y otros. También es el autor de libros de salud exitosos como Never Shower in a Thunderstorm y The 10 Things You Need to Eat.


Studies Suggest People Who Had Covid-19 Should Get Single Vaccine Dose

People Who Have Had Covid Should Get Single Vaccine Dose, Studies Suggest

New studies show that one shot of a vaccine can greatly amplify antibody levels in those who have recovered from the coronavirus.

A nurse supervisor prepared a dose of the Pfizer-BioNTech vaccine at a mass vaccination site in Hartford, Conn., this month.
A nurse supervisor prepared a dose of the Pfizer-BioNTech vaccine at a mass vaccination site in Hartford, Conn., this month.Credit…Christopher Capozziello for The New York Times
Apoorva Mandavilli

  • Feb. 19, 2021Updated 11:49 a.m. ET

Nearly 30 million people in the United States — and probably many others whose illnesses were never diagnosed — have been infected with the coronavirus so far. Should these people still be vaccinated?

Two new studies answer that question with an emphatic yes.

In fact, the research suggests that for these people just one dose of the vaccine is enough to turbocharge their antibodies and destroy the coronavirus — and even some more infectious variants.

The results of these new studies are consistent with the findings of two others published over the past few weeks. Taken together, the research suggests that people who have had Covid-19 should be immunized — but a single dose of the vaccine may be enough.

“I think it’s a really strong rationale for why people who were previously infected with Covid should be getting the vaccine,” said Jennifer Gommerman, an immunologist at the University of Toronto who was not involved in the new research.

A person’s immune response to a natural infection is highly variable. Most people make copious amounts of antibodies that persist for many months. But some people who had mild symptoms or no symptoms of Covid-19 produce few antibodies, which quickly fall to undetectable levels.

The vaccines “even the playing field,” Dr. Gommerman said, so that anyone who has recovered from Covid-19 produces enough antibodies to protect against the virus.

The latest study, which has not yet been published in a scientific journal, analyzed blood samples from people who have had Covid-19. The findings suggested that their immune systems would have trouble fending off B.1.351, the coronavirus variant first identified in South Africa.

But one shot of either the Pfizer-BioNTech or Moderna vaccine significantly changed the picture: It amplified the amount of antibodies in their blood by a thousandfold — “a massive, massive boost,” said Andrew T. McGuire, an immunologist at the Fred Hutchinson Cancer Research Center in Seattle, who led the study.

Flush with antibodies, samples from all of the participants could neutralize not only B.1.351, but also the coronavirus that caused the SARS epidemic in 2003.

In fact, the antibodies seemed to perform better than those in people who had not had Covid and had received two doses of a vaccine. Multiple studies have suggested that the Pfizer-BioNTech and Moderna vaccines are about five times less effective against the variant.

A Covid-19 patient in the intensive care unit of Marian Regional Medical Center in Santa Maria, Calif., this month.
A Covid-19 patient in the intensive care unit of Marian Regional Medical Center in Santa Maria, Calif., this month.Credit…Daniel Dreifuss for The New York Times

The researchers obtained blood samples from 10 volunteers in the Seattle Covid Cohort Study who were vaccinated months after contracting the coronavirus. Seven of the participants received the Pfizer-BioNTech vaccine and three received the Moderna vaccine.

Blood taken about two to three weeks after vaccination showed a significant jump in the amounts of antibodies compared with the samples collected before vaccination. The researchers don’t yet know how long the increased amount of antibodies will persist, but “hopefully, they’ll last a long time,” Dr. McGuire said.

The researchers also saw increases in immune cells that remember and fight the virus, Dr. McGuire said. “It looks pretty clear that we’re boosting their pre-existing immunity,” he said.

In another new study, researchers at New York University found that a second dose of the vaccine did not add much benefit at all for people who have had Covid-19 — a phenomenon that has also been observed with vaccines for other viruses.

In that study, most people had been infected with the coronavirus eight or nine months earlier, but saw their antibodies increase by a hundredfold to a thousandfold when given the first dose of a vaccine. After the second dose, however, the antibody levels did not increase any further.

“It’s a real testament to the strength of the immunologic memory that they get a single dose and have a huge increase,” said Dr. Mark J. Mulligan, director of the N.Y.U. Langone Vaccine Center and the study’s lead author.

In some parts of the world, including the United States, a significant minority of the population has already been infected, Dr. Mulligan noted. “They definitely should be vaccinated,” he said.

It’s unclear whether the thousandfold spike in antibody levels recorded in the lab will occur in real-life settings. Still, the research shows that a single shot is enough to increase the levels of antibodies significantly, said Florian Krammer, an immunologist at the Icahn School of Medicine at Mount Sinai in New York.

Dr. Krammer led another of the new studies, which showed that people who have had Covid-19 and received one dose of a vaccine experienced more severe side effects from the inoculation and had more antibodies compared with those who had not been infected before.

“If you put all four papers together, that’s providing pretty good information about people who already had an infection only needing one vaccination,” Dr. Krammer said.

He and other researchers are trying to persuade scientists at the Centers for Disease Control and Prevention to recommend only one dose for those who have recovered from Covid-19.

A woman receives a vaccine at a drive-through site in Hartford.Credit…Christopher Capozziello for The New York Times

Ideally, those people should be monitored after the first shot in case their antibody levels plummet after some weeks or months, said Dennis R. Burton, an immunologist at the Scripps Research Institute in La Jolla, Calif.

The fact that the supercharged antibodies observed in the new study can fight the 2003 SARS virus suggests that a single dose of the vaccine may have prompted the volunteers’ bodies to produce “broadly neutralizing antibodies” — immune molecules capable of attacking a broad range of related viruses, Dr. Burton said.

He and other scientists have for decades investigated whether broadly neutralizing antibodies can tackle multiple versions of H.I.V. at once. H.I.V. mutates faster than any other virus and quickly evades most antibodies.

The new coronavirus mutates much more slowly, but there are now multiple variants of the virus that seem to have evolved to be more contagious or to thwart the immune system. The new study may provide clues on how to make a single vaccine that stimulates the production of broadly neutralizing antibodies that can destroy all variants of the coronavirus, Dr. Burton said.

Without such a vaccine, scientists will need to tweak the vaccines every time the virus changes significantly. “You’re stuck in a kind of Whac-a-Mole approach,” he said. It will probably take many months if not longer to develop and test that sort of vaccine against the coronavirus, but “that’s the longer-term way to approach this virus.”

People Who Have Had Covid Should Get Single Vaccine Dose, Studies Suggest

People Who Have Had Covid Should Get Single Vaccine Dose, Studies Suggest

New studies show that one shot of a vaccine can greatly amplify antibody levels in those who have recovered from the coronavirus.

A nurse supervisor prepared a dose of the Pfizer-BioNTech vaccine at a mass vaccination site in Hartford, Conn., this month.
A nurse supervisor prepared a dose of the Pfizer-BioNTech vaccine at a mass vaccination site in Hartford, Conn., this month.Credit…Christopher Capozziello for The New York Times
Apoorva Mandavilli

  • Feb. 19, 2021, 9:49 a.m. ET

At least 30 million people in the United States — and probably many others whose illnesses were never diagnosed — have been infected with the coronavirus so far. Should these people still be vaccinated?

Two new studies answer that question with an emphatic yes.

In fact, the research suggests that for these people just one dose of the vaccine is enough to turbocharge their antibodies and destroy the coronavirus — and even some more infectious variants.

The results of these new studies are consistent with the findings of two others published over the past few weeks. Taken together, the research suggests that people who have had Covid-19 should be immunized — but a single dose of the vaccine may be enough.

“I think it’s a really strong rationale for why people who were previously infected with Covid should be getting the vaccine,” said Jennifer Gommerman, an immunologist at the University of Toronto who was not involved in the new research.

A person’s immune response to a natural infection is highly variable. Most people make copious amounts of antibodies that persist for many months. But some people who had mild symptoms or no symptoms of Covid-19 produce few antibodies, which quickly fall to undetectable levels.

The vaccines “even the playing field,” Dr. Gommerman said, so that anyone who has recovered from Covid-19 produces enough antibodies to protect against the virus.

The latest study, which has not yet been published in a scientific journal, analyzed blood samples from people who have had Covid-19. The findings suggested that their immune systems would have trouble fending off B.1.351, the coronavirus variant first identified in South Africa.

But one shot of either the Pfizer-BioNTech or Moderna vaccine significantly changed the picture: It amplified the amount of antibodies in their blood by a thousandfold — “a massive, massive boost,” said Andrew T. McGuire, an immunologist at the Fred Hutchinson Cancer Research Center in Seattle, who led the study.

Flush with antibodies, samples from all of the participants could neutralize not only B.1.351, but also the coronavirus that caused the SARS epidemic in 2003.

In fact, the antibodies seemed to perform better than those in people who had not had Covid and had received two doses of a vaccine. Multiple studies have suggested that the Pfizer-BioNTech and Moderna vaccines are about five times less effective against the variant.

A Covid-19 patient in the intensive care unit of Marian Regional Medical Center in Santa Maria, Calif., this month.
A Covid-19 patient in the intensive care unit of Marian Regional Medical Center in Santa Maria, Calif., this month.Credit…Daniel Dreifuss for The New York Times

The researchers obtained blood samples from 10 volunteers in the Seattle Covid Cohort Study who were vaccinated months after contracting the coronavirus. Seven of the participants received the Pfizer-BioNTech vaccine and three received the Moderna vaccine.

Blood taken about two to three weeks after vaccination showed a significant jump in the amounts of antibodies compared with the samples collected before vaccination. The researchers don’t yet know how long the increased amount of antibodies will persist, but “hopefully, they’ll last a long time,” Dr. McGuire said.

The researchers also saw increases in immune cells that remember and fight the virus, Dr. McGuire said. “It looks pretty clear that we’re boosting their pre-existing immunity,” he said.

In another new study, researchers at New York University found that a second dose of the vaccine did not add much benefit at all for people who have had Covid-19 — a phenomenon that has also been observed with vaccines for other viruses.

In that study, most people had been infected with the coronavirus eight or nine months earlier, but saw their antibodies increase by a hundredfold to a thousandfold when given the first dose of a vaccine. After the second dose, however, the antibody levels did not increase any further.

“It’s a real testament to the strength of the immunologic memory that they get a single dose and have a huge increase,” said Dr. Mark J. Mulligan, director of the N.Y.U. Langone Vaccine Center and the study’s lead author.

In some parts of the world, including the United States, a significant minority of the population has already been infected, Dr. Mulligan noted. “They definitely should be vaccinated,” he said.

It’s unclear whether the thousandfold spike in antibody levels recorded in the lab will occur in real-life settings. Still, the research shows that a single shot is enough to increase the levels of antibodies significantly, said Florian Krammer, an immunologist at the Icahn School of Medicine at Mount Sinai in New York.

Dr. Krammer led another of the new studies, which showed that people who have had Covid-19 and received one dose of a vaccine experienced more severe side effects from the inoculation and had more antibodies compared with those who had not been infected before.

“If you put all four papers together, that’s providing pretty good information about people who already had an infection only needing one vaccination,” Dr. Krammer said.

He and other researchers are trying to persuade scientists at the Centers for Disease Control and Prevention to recommend only one dose for those who have recovered from Covid-19.

A woman receives a vaccine at a drive-through site in Hartford.Credit…Christopher Capozziello for The New York Times

Ideally, those people should be monitored after the first shot in case their antibody levels plummet after some weeks or months, said Dennis R. Burton, an immunologist at the Scripps Research Institute in La Jolla, Calif.

The fact that the supercharged antibodies observed in the new study can fight the 2003 SARS virus suggests that a single dose of the vaccine may have prompted the volunteers’ bodies to produce “broadly neutralizing antibodies” — immune molecules capable of attacking a broad range of related viruses, Dr. Burton said.

He and other scientists have for decades investigated whether broadly neutralizing antibodies can tackle multiple versions of H.I.V. at once. H.I.V. mutates faster than any other virus and quickly evades most antibodies.

The new coronavirus mutates much more slowly, but there are now multiple variants of the virus that seem to have evolved to be more contagious or to thwart the immune system. The new study may provide clues on how to make a single vaccine that stimulates the production of broadly neutralizing antibodies that can destroy all variants of the coronavirus, Dr. Burton said.

Without such a vaccine, scientists will need to tweak the vaccines every time the virus changes significantly. “You’re stuck in a kind of Whac-a-Mole approach,” he said. It will probably take many months if not longer to develop and test that sort of vaccine against the coronavirus, but “that’s the longer-term way to approach this virus.”

How Much Exercise Do You Need for Better Heart Health?

Phys Ed

How Much Exercise Do You Need for Better Heart Health?

The more you do, the better, but even mild exercise like walking produces benefits for cardiovascular health, a large new study found.

Credit…Getty Images
Gretchen Reynolds

  • Feb. 17, 2021, 5:00 a.m. ET

If you want a healthy heart, the more you exercise, the better, according to an encouraging new study of the links between physical activity and cardiovascular disease. It finds that people who often exercise and stay active are much less likely to develop heart disease than people who rarely move, whether that exercise consists of a few minutes a day of jogging or multiple hours a week of walking.

The large-scale study, which relied on objective data about exercise from more than 90,000 adults, bolsters the growing evidence that any almost amount of physical activity seems to be good for cardiovascular health, with no apparent upper limit to the benefits.

For generations, of course, we have known that active people tend to have strong hearts. Back in the late 1940s and early 1950s, Jeremy Morris, a British epidemiologist, famously found that British bus conductors, who spent their days strolling aisles and climbing steps on the double-decker vehicles, were about half as likely to have a heart attack as the buses’ drivers, who sat all day.

Since then, countless epidemiological studies have uncovered similar links between physical activity and cardiovascular problems. In most, greater amounts of physical activity aligned closely with less risk of heart disease. In other words, people who moved a lot tended also to be people with sound hearts and arteries.

In some of those and other studies, though, there was a limit. As the amounts and intensities of people’s exercise rose, the benefits for their hearts plateaued or even plummeted. In a few studies, prolonged intense workouts over the course of years seemed to contribute to an increased risk for heart problems, suggesting that too much exercise may damage the heart. But those studies generally were small and focused on specific groups of people, such as male masters athletes.

Even the larger-scale, epidemiological studies of exercise and heart health, though, often relied on people’s memories and self-reports about their exercise habits, which are not always accurate.

So, some aspects of the relationship between physical activity and cardiovascular health have remained opaque. Can we work out too much for the sake of our hearts? Do men and women get the same cardiovascular-disease risk reductions from the same amounts of physical activity? How much do we actually move around during the day?

Those questions interested Dr. Terence Dwyer, an emeritus professor of epidemiology at the University of Oxford in England, and his colleagues, who long had studied the interplay of lifestyle and disease risk. And they knew of a potential source of increased clarity about possible answers, in the U.K. Biobank.

The U.K. Biobank is an impressively large database of health and lifestyle information about more than 500,000 adult men and women in the United Kingdom. Beginning in 2006, these volunteers provided blood, urine and saliva samples for genetic and medical testing, answered lengthy questionnaires about their lives and completed full health and medical screenings. More than 100,000 of them also agreed to wear activity trackers for a week, to carefully measure how much they moved.

Dr. Dwyer and his colleagues now drew the records for more than 90,000 of the men and women who had worn the trackers, skipping anyone with a known history of heart disease when they joined the study. They divided them into four groups, depending on how many minutes, in total, they moved every week, and how much of this activity was moderate, such as walking, or relatively vigorous, like jogging, as verified by their trackers.

Finally, the researchers gathered data from hospitals and death records about who, among the 90,000 volunteers, developed heart disease in the years after joining the study, and began crosschecking their diagnoses against their activity habits.

To no one’s surprise, being active was protective against heart disease. People in the least-active group, who rarely walked around or formally exercised, were more than twice as likely to have heart disease now as the most-active men and women. Just moving from the least-active group to the not-quite-as-inactive group dropped the risk of heart disease by almost 30 percent, even when the researchers controlled for body composition, smoking, socioeconomic status and other factors.

The researchers also found no upper limit to the benefits. The men and women who moved the most, walking as much as 1,100 minutes a week, or more than two hours a day (a total that included both their actual exercise and everyday activities like grocery shopping or doing housework), while also often working out intensely for 50 minutes or more a week, showed no increased risk for heart problems. Instead, this group enjoyed the greatest risk reductions, with both men and women showing about equal benefits.

The results “provide even stronger evidence than has been available previously” that “physical activity, including vigorous physical activity, is important for reducing the risk of cardiovascular disease,” Dr. Dwyer says. The benefits were “about double what had been found with most self-report studies.”

This study is associational, though, showing that active people happen also to be people with healthy hearts. It does not prove that walks and other activities directly strengthen people’s hearts, only that the two are linked. Dr. Dwyer also points out that the number of people in the study who completed extremely high amounts of intense activity was small, so it remains conceivable that long-term, intense exercise might, at some point, stop being good for hearts. That possibility requires more scrutiny, he says.

But for most of us, he says, increasing our exercise “to much higher levels or more vigorous levels” should substantially reduce our chances, later, for heart disease

Some Teens Volunteer for Covid Vaccine Trials to Get Their Lives Back

To Get Their Lives Back, Teens Volunteer for Vaccine Trials

Immunizing teenagers is a critical part of slowing the pandemic and reaching herd immunity. But enrolling them in clinical trials poses challenges that are very different than wrangling adults.

In Houston, Isabelle King, 14, gets her second dose of the Moderna vaccine from Jallesse Flores, as her twin sister,  Alexandra, looks on.
In Houston, Isabelle King, 14, gets her second dose of the Moderna vaccine from Jallesse Flores, as her twin sister,  Alexandra, looks on.Credit…Brandon Thibodeaux for The New York Times

  • Feb. 16, 2021, 1:55 p.m. ET

To get out of ninth-grade science period one recent Friday, the King twins had an excuse that is so very 2021.

Alexandra and Isabelle, 14, had to miss class — including a test — because they were participating in an actual science experiment: a clinical trial of Moderna’s Covid-19 vaccine to evaluate whether the shot is effective and safe in children ages 12 through 17.

“In science we’re learning about, like, genetics and stuff like that,” said Alexandra during the monitoring period after they’d gotten their shots at a Houston clinic. “So maybe the teacher will say, ‘Oh, you really shouldn’t have to take the test, because you’re contributing to science already.’”

Teenagers contract the novel coronavirus almost twice as often as younger children but vaccines authorized in the United States are mostly for adults — Moderna’s for 18 and older, Pfizer’s for 16 and up. While teenagers don’t become severely ill from the virus as often as adults, research suggests that because they are often asymptomatic and casual about social distancing, they can be efficient spreaders — to one another as well as to adults like parents, grandparents and teachers. Although vaccinating educators will be an important factor in keeping schools open, vaccinating students will also be a key element.

Bottom line: If widespread immunity to the coronavirus is to be achieved, adolescents are critical links. They need a Covid vaccine that works for them.

But teenagers are harder than adults to enroll and keep in clinical trials. They are difficult to wrangle and not so great with compliance, which includes keeping a symptom diary and keeping appointments, as many as six a year, that include blood draws (for some, an instant deal breaker).

To reach students, some researchers have tapped school connections, local pediatricians and social media campaigns. While waiting for appointments in the vaccine research clinics, some teenagers, ignoring advice to keep their vaccine volunteering off of social media, have posted TikTok videos, which have inspired friends to sign up. But the adolescent Covid vaccine trials will be much smaller than the adult trials — two or three thousand subjects instead of 30,000.

“You want to enroll as many kids as necessary but as few as possible, to expose as few as possible,” said Dr. Robert W. Frenck, director of the Vaccine Research Center at Cincinnati Children’s Hospital Medical Center.

To enroll in a trial, children must give “assent,” a legally required, age-appropriate version of “consent.” But researchers must also obtain the parent’s consent or permission. Information sessions for each can be protracted and painstaking. Objection by either child or parent terminates the application.

“Parents may be willing to put themselves in a study but not their children,” said Dr. James Campbell, a pediatric infectious disease expert at the University of Maryland School of Medicine who conducts vaccine trials. “Their key role in life, as parents, is to keep their children safe and they may choose to wait until a vaccine is licensed rather than enroll their child in a trial.”

Often researchers give young subjects an additional caution. Because vaccine disinformation and online personal attacks are so widespread, youth volunteers should avoid discussing their role in the trial on social media.

Audrey, 14, and Sam, 12, brother and sister, are participating in the Pfizer trial in Cincinnati.
Audrey, 14, and Sam, 12, brother and sister, are participating in the Pfizer trial in Cincinnati.Credit…Maddie McGarvey for The New York Times

Although the novel coronavirus has had far less impact on children than older adults, some 2.2 million pediatric cases in the United States have been reported and about 280 children have died, according to the Centers for Disease Control and Prevention. About 2,060 children have contracted a dangerous rare condition related to the coronavirus called multisystem inflammatory syndrome, which can shut down the heart and other organs.

And like anenemy occupation, the pandemic has taken over most children’s lives — shutting down in-person school, sports, socializing. That has prompted some teenagers, who otherwise feel so powerless, to fight back by volunteering for vaccine trials.

Sam, 12, who entered the Pfizer trial at Cincinnati Children’s hospital, said he wanted to participate “because it would be helping science and beat the pandemic. And it was my way of saying thank you to the frontline workers who are keeping us healthy.”

His sister, Audrey, 14, who is also in the study, said, “I thought this would be a really good story I could tell my children and grandchildren — that I tried to help create the vaccine.”

“And I also thought it is important to have people of different ages and races represented,” added Audrey, who, like her brother, is Asian. (Their mother, Rachel, a nurse researcher who volunteered for a vaccine trial, asked that their last names be withheld for privacy reasons.)

Overall, the teen trials may be less diverse, because results from adult trials showed no discernible difference in outcome by race. And because the adult trials were so successful, up to two-thirds of teenagers may be offered the actual vaccine rather than a placebo.

Pfizer, whose trial is fully enrolled, expects results from its trials for children ages 12 through 15 in the first quarter of this year, which it will then submit to the Food and Drug Administration for review. Moderna is still recruiting for its adolescent trials, with data anticipated sometime this summer. Other companies expect to start adolescent trials soon. Shortly after, researchers will open trials for children as young as 5, most likely with more modest doses.

As in any medical trial, investigators are evenhanded when discussing risks and benefits. Rather than lecturing young subjects, Dr. Campbell, whose clinic will conduct a Moderna trial for younger children, engages them in conversation.

“Do you remember your tetanus shot? Tell me about it,” he might say. And then, “Here’s how this is similar and how it’s different.” He wants to make sure the teenager is actively involved in decision-making. “We always say, ‘Don’t do this for your parents.’ ”

Dr. Sarah Hasan, lead recruiter for DM Clinical Research, which oversees the Houston Fights Covid campaign and most of the city’s vaccine trials, said that information sessions for adolescents and adults differ strikingly. She has more fun with the teenagers.

“Usually adults will skim the form, ask a few questions and they’re done,” she said. “But kids ask way more questions than adults and they’re actually listening, which is pretty nice.”

“Of course,” she added, “they also want to know if the doses will turn them into zombies.”

During adult trials, when participants were leery and results unknown, no-shows for appointments were common, Dr. Hasan said. But teenagers “come on time and are being super-compliant.”

Another issue in enrollment is compensation. Researchers typically offer volunteers money to cover time and travel expenses but the amount cannot be substantial enough to seem like an inducement. The going rate is about $15 an hour. The Cincinnati Pfizer trial compensates parents too, reasoning that they contribute time and money, as unofficial chauffeurs for the young subjects.

In Houston, the King sisters were already fantasizing about how they would spend the money.

Alexandra’s impulses were immediately generous. Now she could buy presents for others that her father typically paid for. “It’ll definitely be something nice to do, like, I earned it by getting a shot in the arm to help people. And now at least I can buy Christmas gifts for my mom,” she said.

Jonah Proctor, 15, awaits his shot at a Covid vaccine trial site in Houston.Credit…Brandon Thibodeaux for The New York Times

Her sister Isabelle hastily chimed in that, of course, she too would use the money for something selfless. Then she did allow, “Well, my closet could use an update.”

This summer, Monica Mitchell, a community health educator who works for Cincinnati Children’s, participated in a Pfizer vaccine trial. Her daughter Melanie, a high school junior, was deeply curious, but at that point, volunteers had to be at least 16 years old. On the day she turned 16, Melanie called to enroll.

Both mother and daughter have become ambassadors for the vaccine. “Someone said to me, ‘You’re doing the white man’s work,’ ” recounted Melanie, who is Black. “And I said, ‘No, it’s the opposite. I’m doing the work for my people.’ ”

Dr. Mitchell, who is also a pediatric psychologist and researcher, got some blowback for allowing her daughter to enter a vaccine trial. “Some relatives asked, “‘Why would you do that?’ But at least they understand that Melanie is fairly independent and they know she made her own decision,” Dr. Mitchell said.

Like most trial volunteers, children worry about side effects. Sure enough, after Sam got the second dose from Cincinnati Children’s hospital, he had a rough go of it.

In the middle of the night he woke with a throbbing headache. Then chills, a low-grade fever, muscle aches.

“He looked miserable,” said his mother, Rachel. “It’s one thing to talk theoretically about side effects but it was hard as a mom to see him feeling really bad.”

She felt guilty for having encouraged him to participate. “I’m so sorry,” she said.

Sam was mystified by her reaction. “I’m so happy,” he replied. “This means I got the real thing!”

Audrey, his sister, felt fine after her dose. “I’m jealous,” she said.

Covid Vaccines for Kids Are Coming, but Not for Many Months

Covid Vaccines for Kids Are Coming, but Not for Many Months

Pfizer and Moderna are testing their vaccines on children 12 and older and hope to have results by the summer.

A 15-year-old participating in Moderna’s teen Covid vaccine trial received a shot in Houston this month.
A 15-year-old participating in Moderna’s teen Covid vaccine trial received a shot in Houston this month.Credit…Brandon Thibodeaux for The New York Times
Apoorva Mandavilli

  • Feb. 12, 2021, 5:00 a.m. ET

As adults at high risk for Covid-19 line up to be immunized against the coronavirus, many parents want to know: When will my child get a vaccine?

The short answer: Not before late summer.

Pfizer and Moderna have enrolled children 12 and older in clinical trials of their vaccines and hope to have results by the summer. Depending on how the vaccines perform in that age group, the companies may then test them in younger children. The Food and Drug Administration usually takes a few weeks to review data from a clinical trial and authorize a vaccine.

Three other companies — Johnson & Johnson, Novavax and AstraZeneca — also plan to test their vaccines in children, but are further behind.

When researchers test drugs or vaccines in adults first, they typically then move down the age brackets, watching for any changes in the effective dose and for unexpected side effects.

“It would be pretty unusual to start going down into children at an early stage,” said Dr. Emily Erbelding, an infectious diseases physician at the National Institutes of Health who oversees testing of Covid-19 vaccines in special populations.

Some vaccines — those that protect against pneumococcal or meningococcal bacteria or rotavirus, for example — were tested in children first because they prevent pediatric diseases. But it made sense for coronavirus vaccines to be first tested in and authorized for adults because the risk of severe illness and death from Covid-19 increases sharply with age, said Paul Offit, a professor at the University of Pennsylvania and a member of the F.D.A.’s vaccine advisory panel.

“We’re trying to save lives, keep people out of the I.C.U., keep them from dying,” Dr. Offit said. That means prioritizing vaccines for the oldest people and for those with underlying conditions.

People younger than 21 account for about one-quarter of the population in the United States, but they make up less than 1 percent of deaths from Covid-19. Still, about 2 percent of children who get Covid-19 require hospital care, and at least 227 children in the United States have died of the disease.

“It is a significant disease in children, just not necessarily when you compare it to adults,” said Dr. Kristin Oliver, a pediatrician and vaccine expert at Mount Sinai Hospital in New York.

Children will also need to be vaccinated in order for the United States to approach herd immunity — that long-promised goal at which the pandemic slows to a halt because the virus runs out of people to infect.

Scientists have estimated that 70 to 90 percent of the population might need to be immunized against the coronavirus to reach herd immunity, especially with more contagious variants expected to circulate widely in the country.

“Not all adults can get the vaccine because there’s some reluctance, or there’s maybe even some vulnerable immune systems that just don’t respond,” Dr. Erbelding said. “I think we have to include children if we’re going to get to herd immunity.”

It will also be important to immunize children in racial and ethnic populations that are hit hardest by the pandemic, she added.

Abhinav, 12, a participant in the Pfizer vaccine trial at Cincinnati Children’s Hospital last month.
Abhinav, 12, a participant in the Pfizer vaccine trial at Cincinnati Children’s Hospital last month.Credit…Cincinnati Children’s Hospital

Pfizer and Moderna’s clinical trials in adults each enrolled about 50,000 participants. They had to be that large in order to show significant differences between the volunteers who received a vaccine and those who got a placebo. But because it is rarer for children to become seriously ill with Covid-19, that kind of trial design in children would not be feasible, because it would require many more participants to show an effect.

Instead, the companies will look at vaccinated children for signs of a strong immune response that would protect them from the coronavirus.

The Pfizer-BioNTech vaccine was authorized in December for anyone 16 and older. The company has continued its trial with younger volunteers, recruiting 2,259 adolescents from 12 to 15 years of age. Teenagers are roughly twice as likely to be infected with the coronavirus as younger children, according to the Centers for Disease Control and Prevention.

Results from that trial should be available by summer, said Keanna Ghazvini, a spokeswoman for Pfizer.

“Moving below 12 years of age will require a new study and potentially a modified formulation or dosing schedule,” Ms. Ghazvini said. Those trials will most likely start later in the year, but the plans will be made final after the company has data from older children, she added.

Moderna’s vaccine, which was also authorized in December, is on a similar track for pediatric testing. In December, the company began testing adolescents ages 12 through 17, and plans to enroll 3,000 volunteers in this age group. The company expects results “around midyear 2021,” said Colleen Hussey, a spokeswoman for Moderna.

Based on the results, Moderna plans to assess the vaccine later this year in children between the ages of 6 months and 11 years.

Infants may have some antibodies at birth from vaccinated or infected mothers, but that maternal protection is unlikely to last through the first year of age. And with their relatively weak immune systems, babies might be particularly susceptible to infection if community transmission is high.

The trials will also assess the vaccine’s safety in children — and hopefully ease any fears that parents have. One-third of adults in the United States have said they do not plan to have their children immunized against the coronavirus, according to a recent poll conducted by Verywell Health.

Given the low risk of Covid-19 in children, some parents might be skeptical of the urgency to inoculate their children with a brand-new jab, Dr. Offit said. “For that reason, the vaccine would have to be held to a very high standard of safety,” he said.

More than 42 million people in the United States have been immunized so far, with few lasting side effects. And the F.D.A. has set up multiple systems to carefully monitor any serious reactions to the vaccine.

“They’re really looking at the data very, very closely,” Dr. Oliver said. “As a pediatrician and a mom, I have really good confidence that those systems work.”

Once a vaccine for children is available, schools can reintroduce extracurricular activities that involve close contact, like band practice, team sports and choir. But in the meantime, there is ample evidence that schools can reopen with other precautions in place, Dr. Oliver said.

“I don’t think we need to anticipate having a vaccine in order to open schools in the fall,” she said. “We should be planning now for opening schools.”

Dr. Oliver also urged parents to make sure children are immunized for other diseases. According to the C.D.C., orders for non-flu childhood vaccines through the Vaccines for Children Program are down approximately 10.3 million doses over all.

“Now’s the time to really catch up on missed doses of those vaccines,” she said. “Measles, HPV, tetanus boosters, pertussis boosters — all of that is really important.”

Could a Single Vaccine Work Against All Coronaviruses?

Could a Single Vaccine Work Against All Coronaviruses?

Scientists are working on a shot that could protect against Covid-19, its variants, certain seasonal colds — and the next coronavirus pandemic.

Tara Gallion, a licensed practical nurse, prepared to administer doses of the Moderna Covid vaccine in Mound Bayou, Miss., last month.
Tara Gallion, a licensed practical nurse, prepared to administer doses of the Moderna Covid vaccine in Mound Bayou, Miss., last month.Credit…Rory Doyle for The New York Times
Carl Zimmer

  • Feb. 9, 2021, 11:26 a.m. ET

The invention of Covid-19 vaccines will be remembered as a milestone in the history of medicine, creating in a matter of months what had before taken up to a decade. But Dr. Kayvon Modjarrad, the director of Emerging Infectious Diseases Branch at Walter Reed Army Institute of Research in Silver Springs, Md., isn’t satisfied.

“That’s not fast enough,” he said. More than 2.3 million people around the world have died, and many countries will not have full access to the vaccines for another year or two: “Fast — truly fast — is having it there on day one.”

There will be more coronavirus outbreaks in the future. Bats and other mammals are rife with strains and species of this abundant family of viruses. Some of these pathogens will inevitably spill over the species barrier and cause new pandemics. It’s only a matter of time.

Dr. Modjarrad is one of many scientists who for years have been calling for a different kind of vaccine: one that could work against all coronaviruses. Those calls went largely ignored until Covid-19 demonstrated just how disastrous coronaviruses can be.

Now researchers are starting to develop prototypes of a so-called pancoronavirus vaccine, with some promising, if early, results from experiments on animals. Dr. Eric Topol, a professor of molecular medicine at the Scripps Research Institute in San Diego, thinks scientists should join together in another large-scale vaccine-creation project immediately.

“We have to get a real work force to accelerate this, so we can have it this year,” he said. Dr. Topol and Dennis Burton, a Scripps immunologist, called for this project on broad coronavirus vaccines on Monday in the journal Nature.

After coronaviruses were first identified in the 1960s, they did not become a high priority for vaccine makers. For decades it seemed as if they only caused mild colds. But in 2002, a new coronavirus called SARS-CoV emerged, causing a deadly pneumonia called severe acute respiratory syndrome, or SARS. Scientists scrambled to make a vaccine for it.

Dr. Kayvon Modjarrad, director of emerging infectious diseases at the Walter Reed Army Institute, during a coronavirus briefing in March.
Dr. Kayvon Modjarrad, director of emerging infectious diseases at the Walter Reed Army Institute, during a coronavirus briefing in March.Credit…Yasin Ozturk/Anadolu Agency, via Getty Images

Since no one had made a coronavirus vaccine for humans before, there was a huge amount to learn about its biology. Eventually, researchers chose a target for immunity: a protein on the surface of the virus, called spike. Antibodies that stick to the spike can prevent the coronavirus from entering cells and stop an infection.

Public health officials in Asia and elsewhere did not wait for the invention of a SARS vaccine to get to work, however. Their quarantines and other efforts proved remarkably effective. In a matter of months, they wiped out SARS-CoV, with only 774 deaths along the way.

The danger of coronaviruses became even clearer in 2012, when a second species spilled over from bats, causing yet another deadly respiratory disease called MERS. Researchers started work on MERS vaccines. But some researchers wondered if making a new vaccine for each new coronavirus — what Dr. Modjarrad calls “the one bug, one drug approach” — was the smartest strategy. Wouldn’t it be better, they thought, if a single vaccine could work against SARS, MERS and any other coronavirus?

That idea went nowhere for years. MERS and SARS caused relatively few deaths, and were soon eclipsed by outbreaks of other viruses such as Ebola and Zika.

In 2016, Maria Elena Bottazzi, a virologist at Baylor College of Medicine, and her colleagues applied for support from the American government to develop a pancoronavirus vaccine, but did not receive it. “They said there’s no interest in pancorona,” Dr. Bottazzi recalled.

Her team even lost funding for developing a SARS vaccine after they showed that it worked in mice, was not toxic to human cells and could be manufactured at scale. A coronavirus that had disappeared from view simply wasn’t a top priority.

Without enough money to start clinical trials, the scientists stored their SARS vaccine in a freezer and moved on to other research. “It’s been a struggle,” Dr. Bottazzi said.

Dr. Matthew Memoli, a virologist at the National Institute of Allergy and Infectious Diseases, looks back at those decisions as an enormous blunder. “It’s a failure of our system of science,” he said. “Funders tend to chase after shiny objects.”

A transmission electron micrograph of the Middle East Respiratory Syndrome.Credit…NIAID

Three years later, a third dangerous coronavirus emerged: the SARS-CoV-2 strain that causes Covid-19. Although this virus has a much lower fatality rate than its cousins that cause SARS and MERS, it does a far better job of spreading from person to person, resulting in more than 106 million documented cases around the world and still climbing.

All the lessons that researchers had learned about coronaviruses helped them move quickly to make new vaccines for SARS-CoV-2. Dr. Bottazzi and her colleagues used the technology they had created to make SARS vaccines to make one for Covid-19, which is now in early clinical trials.

Other researchers used even newer methods to move faster. The German company BioNTech created a genetic molecule called messenger RNA that encoded the spike protein. Partnering with Pfizer, the companies received U.S. government authorization for their vaccine in just 11 months. The previous record for a vaccine, against chickenpox, was four years.

Although the Covid-19 pandemic is still far from over, a number of researchers are calling for preparations for the next deadly coronavirus.

“This has already happened three times,” said Daniel Hoft, a virologist at Saint Louis University. “It’s very likely going to happen again.”

Researchers at VBI vaccines, a Cambridge-based company, took a small step toward a pancoronavirus vaccine last summer. They created virus-like shells studded with spike proteins from the three coronaviruses that caused SARS, MERS and Covid-19.

When the researchers injected this three-spike vaccine into mice, the animals made antibodies that worked against all three coronaviruses. Intriguingly, some of those antibodies could also latch onto a fourth human coronavirus that causes seasonal colds — even though that virus’s spike proteins were not included in the vaccine. The scientists have made this data public but have not yet published it in a scientific journal.

David Anderson, VBI’s chief scientific officer, said it was not clear why the vaccine worked this way. One possibility is that an immune cell presented with several versions of a protein at once doesn’t make antibodies against just one. Instead, it makes a compromise antibody that works against them all.

“You’re educating it,” Dr. Anderson said, although he cautioned that this was speculation for now.

Last month, Pamela Bjorkman, a structural biologist at Caltech, and her colleagues published a more extensive experiment with a universal coronavirus vaccine in the journal Science. The researchers attached only the tips of spike proteins from eight different coronaviruses to a protein core, known as a nanoparticle. After injecting these nanoparticles into mice, the animals generated antibodies that could stick to all eight of the coronaviruses — and to four other coronaviruses that the scientists had not used in the vaccine.

Sarah Clarke, a lab technician at the Sequencing and Genomic Technologies Shared Resource at Duke University, working with positive coronavirus samples.Credit…Pete Kiehart for The New York Times

Dr. Modjarrad is leading a team at Walter Reed developing another vaccine based on a nanoparticle studded with protein fragments. They anticipate starting clinical trials on volunteers next month. Although the vaccine currently uses protein fragments only from SARS-CoV-2 spikes, Dr. Modjarrad and his colleagues are preparing to retool it as a pancoronavirus vaccine.

Dr. Hoft of Saint Louis University is working on a universal vaccine that does not rely on antibodies to the spike protein. Collaborating with Gritstone Oncology, a California-based biotech company, he has created a vaccine that prompts cells to make surface proteins that might alert the immune system as if a coronavirus — any coronavirus — were present. They are now preparing a clinical trial to see if it is effective against SARS-CoV-2.

“We are interested to develop maybe a third-generation vaccine, which would be on the shelf and ready for the future outbreak,” Dr. Hoft said.

Dr. Topol believes scientists should also explore another strategy: searching for pancoronavirus antibodies made by our own bodies during infections.

Researchers studying H.I.V. and other viruses have discovered, amid the billions of antibodies made during an infection, rare types that work against a huge range of related strains. It might be possible to create vaccines that coax the body to make abundant amounts of these broadly neutralizing antibodies.

Coronaviruses are similar enough to each other, Dr. Topol said, that it might not be that hard to build vaccines that make broadly neutralizing antibodies. “This is an easy family of viruses to take down,” he said.

The search for a pancoronavirus vaccine may take longer than Dr. Topol’s sunny expectations. But even if it takes a few years, it could help prepare the world for the next coronavirus that jumps the species barrier.

“I think we can have vaccines to prevent pandemics like this,” Dr. Memoli said. “None of us wants to go through this again. And we don’t want our children to go through this again, or our grandchildren, or our descendants 100 years from now.”

People With Dementia Are Twice as Likely to Get Covid, Huge Study Finds

People With Dementia Are Twice as Likely to Get Covid, Huge Study Finds

The analysis of nearly 62 million electronic medical records in the U.S. also found that Black people with dementia were at an even greater risk.

Lynda Hartman, 75, visited her 77-year-old husband, Len Hartman, who lives with dementia, in a hug tent outside an assisted living center in Louisville, Colo., this month.
Lynda Hartman, 75, visited her 77-year-old husband, Len Hartman, who lives with dementia, in a hug tent outside an assisted living center in Louisville, Colo., this month.Credit…Thomas Peipert/Associated Press
Pam Belluck

  • Feb. 9, 2021, 7:00 a.m. ET

People with dementia had significantly greater risk of contracting the coronavirus, and they were much more likely to be hospitalized and die from it, than people without dementia, a new study of millions of medical records in the United States has found.

Their risk could not be entirely explained by characteristics common to people with dementia that are known risk factors for Covid-19: old age, living in a nursing home and having conditions like obesity, asthma, diabetes and cardiovascular disease. After researchers adjusted for those factors, Americans with dementia were still twice as likely to have gotten Covid-19 as of late last summer.

“It’s pretty convincing in suggesting that there’s something about dementia that makes you more vulnerable,” said Dr. Kristine Yaffe, a professor of neurology and psychiatry at the University of California, San Francisco, who was not involved in the study.

The study found that Black people with dementia were nearly three times as likely as white people with dementia to become infected with the virus, a finding that experts said most likely reflected the fact that people of color generally have been disproportionately harmed during the pandemic.

“This study highlights the need to protect patients with dementia, especially those who are Black,” the authors wrote.

Maria Carrillo, chief science officer of the Alzheimer’s Association, which runs the journal that published the study, Alzheimer’s and Dementia, said in an interview, “One of the things that has come from this Covid situation is that we should be pointing out these disparities.”

The study was led by researchers at Case Western Reserve University who analyzed electronic health records of 61.9 million people age 18 and older in the United States from Feb. 1 through Aug. 21, 2020. The data, collected by IBM Watson Health Explorys, came from 360 hospitals and 317,000 health care providers across all 50 states and represented a fifth of the American population, the authors said.

Rong Xu, a professor of biomedical informatics at Case Western and the senior author of the study, said there had been speculation about whether people with dementia were more prone to infection and harm from Covid-19.

“We thought, ‘We have the data, we can just test this hypothesis,’” Dr. Xu said.

The researchers found that out of 15,770 patients with Covid-19 in the records analyzed, 810 of them also had dementia. When the researchers adjusted for general demographic factors — age, sex and race — they found that people with dementia had more than three times the risk of getting Covid-19. When they adjusted for Covid-specific risk factors like nursing home residency and underlying physical conditions, the gap closed somewhat, but people with dementia were still twice as likely to become infected.

Experts and the study authors said the reasons for this vulnerability might include cognitive and physiological factors.

“Folks with dementia are more dependent on those around them to do the safety stuff, to remember to wear a mask, to keep people away through social distancing,” said Dr. Kenneth Langa, a professor of medicine at the University of Michigan, who was not involved in the study. “There is the cognitive impairment and the fact that they are more socially at risk,” he said.

Dr. Yaffe said there could also be a “frailty element” to people with dementia, including a lack of mobility and muscle tone, that could affect their resilience to infections.

Dr. Carrillo noted that coronavirus infection was associated with an inflammatory response that has been shown to affect blood vessels and other aspects of the circulatory system. Many people with dementia already have vascular impairment, which may be compounded or amplified by Covid-19.

Indeed, the study authors subdivided patients by the type of dementia listed in the electronic records and found that people designated as having vascular dementia had a greater risk for infection than people designated as having Alzheimer’s disease or other types.

But Dr. Langa and Dr. Yaffe cautioned that there was significant overlap between types of dementia. Many patients have both Alzheimer’s pathology and vascular pathology, they said, and physicians who are not specialists may not distinguish subtypes in providing codes for electronic records.

In examining the risk of hospitalization and death for Covid patients with dementia, the researchers did not adjust for demographics like age or whether they lived in nursing homes or had underlying medical conditions. They found that Covid patients with dementia were 2.6 times as likely to have been hospitalized during the first six months of the pandemic as those without dementia. They were 4.4 times as likely to die.

Black people with Covid-19 and dementia were significantly more likely to be hospitalized than white people who had both diseases. The authors did not find a significant difference in the mortality rate for Black and white coronavirus patients with dementia, although they wrote that the number of deaths analyzed, 170, might be too small to provide a solid conclusion about that.

Experts noted that one limitation to the study was that researchers did not have access to socioeconomic information, which could provide increased understanding of patients’ risk factors.

Dr. Langa also noted that the data reflected only people who have interacted with the health care system, so it doesn’t include “more isolated and poorer patients that have a harder time getting to doctors.”

Consequently, he said, the study may be “an underestimate of the greater Covid infection risk for those with dementia.”

Alzheimer’s Prediction May Be Found in Writing Tests

Alzheimer’s Prediction May Be Found in Writing Tests

IBM researchers trained artificial intelligence to pick up hints of changes in language ahead of the onset of neurological diseases.

An M.R.I. scan of a patient over the age of 60 with Alzheimer’s disease.
An M.R.I. scan of a patient over the age of 60 with Alzheimer’s disease.Credit…Zephyr/Science Source
Gina Kolata

  • Feb. 1, 2021, 10:41 a.m. ET

Is it possible to predict who will develop Alzheimer’s disease simply by looking at writing patterns years before there are symptoms?

According to a new study by IBM researchers, the answer is yes.

And, they and others say that Alzheimer’s is just the beginning. People with a wide variety of neurological illnesses have distinctive language patterns that, investigators suspect, may serve as early warning signs of their diseases.

For the Alzheimer’s study, the researchers looked at a group of 80 men and women in their 80s — half had Alzheimer’s and the others did not. But, seven and a half years earlier, all had been cognitively normal.

The men and women were participants in the Framingham Heart Study, a long-running federal research effort that requires regular physical and cognitive tests. As part of it, they took a writing test before any of them had developed Alzheimer’s that asks subjects to describe a drawing of a boy standing on an unsteady stool and reaching for a cookie jar on a high shelf while a woman, her back to him, is oblivious to an overflowing sink.

The researchers examined the subjects’ word usage with an artificial intelligence program that looked for subtle differences in language. It identified one group of subjects who were more repetitive in their word usage at that earlier time when all of them were cognitively normal. These subjects also made errors, such as spelling words wrong or inappropriately capitalizing them, and they used telegraphic language, meaning language that has a simple grammatical structure and is missing subjects and words like “the,” “is” and “are.”

The members of that group turned out to be the people who developed Alzheimer’s disease.

The A.I. program predicted, with 75 percent accuracy, who would get Alzheimer’s disease, according to results published recently in The Lancet journal EClinicalMedicine.

“We had no prior assumption that word usage would show anything,” said Ajay Royyuru, vice president of health care and life sciences research at IBM Thomas J. Watson Research Center in Yorktown Heights, N.Y., where the A.I. analysis was done.

Alzheimer’s researchers were intrigued, saying that when there are ways to slow or stop the illness — a goal that so far remains elusive — it will be important to have simple tests that can warn, early on, that without intervention a person will develop the progressive brain disease.

“What is going on here is very clever ” said Dr. Jason Karlawish, an Alzheimer’s researcher at the University of Pennsylvania. “Given a large volume of spoken or written speech, can you tease out a signal?”

For years, researchers have analyzed speech and voice changes in people who have symptoms of neurological diseases — Alzheimer’s, ALS, Parkinson’s, frontotemporal dementia, bipolar disease and schizophrenia, among others.

But, said Dr. Michael Weiner, who researches Alzheimer’s disease at the University of California, San Francisco, the IBM report breaks new ground.

“This is the first report I have seen that took people who are completely normal and predicted with some accuracy who would have problems years later,” he said.

The hope is to extend the Alzheimer’s work to find subtle changes in language use by people with no obvious symptoms but who will go on to develop other neurological diseases.

Examples from the Framingham Heart Study, including (a) an unimpaired sample, (b) an impaired sample showing telegraphic speech and lack of punctuation and (c) an even more impaired sample showing in addition significant misspellings and minimal grammatic complexity.
Examples from the Framingham Heart Study, including (a) an unimpaired sample, (b) an impaired sample showing telegraphic speech and lack of punctuation and (c) an even more impaired sample showing in addition significant misspellings and minimal grammatic complexity.Credit…Elif Eyigoz et al., The Lancet 2020

Each neurological disease produces unique changes in speech, which probably occur long before the time of diagnosis, said Dr. Murray Grossman, a professor of neurology at the University of Pennsylvania and the director of the university’s frontotemporal dementia center.

He has been studying speech in patients with a behavioral form of frontotemporal dementia, a disorder caused by progressive loss of nerves in the brain’s frontal lobes. These patients exhibit apathy and declines in judgment, self control and empathy that have proved difficult to objectively quantify.

Speech is different, Dr. Grossman said, because changes can be measured.

Early in the course of that disease, there are changes in the pace of the patients’ speech, with pauses distributed seemingly at random. Word usage changes, too — patients use fewer abstract words.

These alterations are directly linked to changes in the frontotemporal parts of the brain, Dr. Grossman said. And they appear to be universal, not unique to English.

Dr. Adam Boxer, director of the neurosciences clinical research unit at the University of California, San Francisco, is also studying frontotemporal dementia. His tool is a smartphone app. His subjects are healthy people who have inherited a genetic predisposition to develop the disease. His method is to show subjects a picture and ask them to record a description of what they see.

“We want to measure very early changes, five to 10 years before they have symptoms,” he said.

“The nice thing about smartphones,” Dr. Boxer added, “is that you can do all kinds of things.” Researchers can ask people to talk for a minute about something that happened that day, he said, or to repeat sounds like tatatatata.

Dr. Boxer said he and others were focusing on speech because they wanted tests that were noninvasive and inexpensive.

Dr. Cheryl Corcoran, a psychiatrist at Icahn School of Medicine at Mount Sinai in New York, hopes to use speech changes to predict which adolescents and young adults at high risk for schizophrenia may go on to develop the disease.

Guillermo Cecchi, a principal researcher for computational psychiatry and neuroimaging at IBM.Credit…IBM Research

Drugs to treat schizophrenia may help those who are going to develop the disease, but the challenge is to identify who the patients will be. A quarter of people with occasional symptoms saw them go away, and about a third never progressed to schizophrenia although their occasional symptoms persisted.

Guillermo Cecchi, an IBM researcher who was also involved in the recent Alzheimer’s research, studied speech in 34 of Dr. Corcoran’s patients, looking for “flight of ideas,” meaning the instances when patients were off track when talking and spinning off ideas in different directions. He also looked for “poverty of speech,” meaning the use of simple syntactic structures and short sentences.

In addition, Dr. Cecchi and his colleagues studied another small group consisting of 96 patients in Los Angeles — 59 of whom had occasional delusions. The rest were healthy people and those with schizophrenia. He asked these subjects to retell a story that they had just heard, and he looked for the same telltale speech patterns.

In both groups, the artificial intelligence program could predict, with 85 percent accuracy, which subjects developed schizophrenia three years later.

“It’s been a lot of small studies finding the same signals,” Dr. Corcoran said. At this point, she said, “we are not at the point yet where we can tell people if they are at risk or not.”

Dr. Cecchi is encouraged, although he realizes the studies are still in their infancy.

“For us, it is a priority to do the science correctly and at scale,” he said. “We should have many more samples. There are more than 60 million psychiatric interviews in the U.S. each year but none of those interviews are using the tools we have.”

Evidence Builds That Pregnant Women Pass Covid Antibodies to Newborns

Evidence Builds That Pregnant Women Pass Covid Antibodies to Newborns

A new study suggests that protective antibodies can be transferred through the placenta, and the baby may receive more of them if a mother is infected with Covid earlier in her pregnancy.

A woman  in McAllen, Tex., who tested positive for Covid-19 while she was pregnant. Studies suggest that pregnant women infected with the coronavirus can pass antibodies to their babies. 
A woman in McAllen, Tex., who tested positive for Covid-19 while she was pregnant. Studies suggest that pregnant women infected with the coronavirus can pass antibodies to their babies. Credit…Carolyn Cole/Getty Images
Christina Caron

  • Jan. 29, 2021, 9:04 p.m. ET

One of the many big questions scientists are trying to untangle is whether people who get Covid-19 during pregnancy will pass on some natural immunity to their newborns.

Recent studies have hinted that they might. And new findings, published Friday in the journal JAMA Pediatrics, provide another piece of the puzzle, offering more evidence that Covid-19 antibodies can cross the placenta.

“What we have found is fairly consistent with what we have learned from studies of other viruses,” said Scott E. Hensley, an associate professor of microbiology at the Perelman School of Medicine at the University of Pennsylvania and one of the senior authors of the study.

Additionally, he added, the study suggests that women are not only transferring antibodies to their fetuses, but also transferring more antibodies to their babies if they are infected earlier in their pregnancies. This might have implications for when women should be vaccinated against Covid-19, Dr. Hensley said, adding that vaccinating women earlier in pregnancy might offer more protective benefits, “but studies actually analyzing vaccination among pregnant women need to be completed.”

In the study, researchers from Pennsylvania tested more than 1,500 women who gave birth at Pennsylvania Hospital in Philadelphia between April and August of last year. Of those, 83 women were found to have Covid-19 antibodies — and after they gave birth, 72 of those babies tested positive for Covid-19 antibodies via their cord blood, regardless of whether their mothers had symptoms.

According to Dr. Karen Puopolo, an associate professor of pediatrics at the University of Pennsylvania and one of the senior authors of the study, about half of those babies had antibody levels that were as high or higher than those found in their mother’s blood, and in about a quarter of the cases, the antibody levels in the cord blood was 1.5 to 2 times higher than the mother’s concentrations.

“That’s fairly efficient,” Dr. Puopolo said.

The researchers also observed that the longer the time period between the start of a pregnant woman’s Covid-19 infection and her delivery, the more antibodies were transferred, a finding that has been noted elsewhere.

The antibodies that crossed the placenta were immunoglobulin G, or IgG, antibodies, the type that are made days after getting infected and are thought to offer long-term protection against the coronavirus.

None of the babies in this study were found to have immunoglobulin M, or IgM, antibodies, which are typically only detected soon after an infection, suggesting that the babies hadn’t been infected with the coronavirus.

Experts don’t yet know if the amount of antibodies that passed on to the babies were enough to prevent newborns from getting Covid-19. And because only a few of the babies in the study were born prematurely, the researchers can’t say whether babies who are born early might miss out on those protective antibodies. The study authors also noted that because their results were from just one facility, the findings would need to be further replicated.

The placenta is a complex organ, and one that has been understudied, said Dr. Denise Jamieson, an obstetrician at Emory University in Atlanta and a member of the Covid expert group at the American College of Obstetricians and Gynecologists, who was not involved with the study.

And more research is needed to better understand whether vaccine-generated antibodies behave comparably to antibodies from Covid-19 infection, said Dr. Andrea G. Edlow, an assistant professor of obstetrics, gynecology and reproductive biology at Harvard Medical School.

In a study published in the journal Cell in December, for instance, Dr. Edlow and her colleagues found that Covid-19 antibodies from a natural infection might cross the placenta less efficiently than the antibodies produced after vaccination for flu and whooping cough (pertussis).

“What we really want to know is, do antibodies from the vaccine efficiently cross the placenta and protect the baby, the way we know happens in influenza and pertussis,” Dr. Jamieson said.

Experts do not know whether the Covid vaccine will work in this way, in part because pregnant women were excluded from the initial clinical trials.

“It’s plausible that the Covid vaccine will offer protection to both pregnant mothers and their infants,” said Dr. Mark Turrentine, a member of the Covid expert group at A.C.O.G. “To me,” he added, “this study highlights that inclusion of pregnant women in clinical trials such as the Covid-19 vaccine is essential, particularly when the benefit of vaccination is greater than the potential risk of a life-threatening disease.”

A Living Legacy in Pediatric Cancer Research

Living With Cancer

Tyler Trent’s Living Legacy

Even as he was dying, he worked to raise awareness of pediatric cancer. Now scientists are using his cells to help others.

From left, Tyler Trent, Dr. Jamie L. Renbarger and Dr. Karen E. Pollok.
From left, Tyler Trent, Dr. Jamie L. Renbarger and Dr. Karen E. Pollok.Credit…Kelly Trent

  • Jan. 21, 2021, 5:00 a.m. ET

Approximately 85 percent of children with cancer are cured. However, about 15 percent confront the sort of aggressive disease that cut short the life of Tyler Trent at the age of 20 on Jan. 1, 2019. “One hundred years down the line, maybe my legacy could have an impact”: so Tyler said about his efforts to raise awareness of the need for further research in pediatric oncology. Two years after his death, Tyler’s physicians continue to help incurable as well as cured children lead longer and better lives.

Back in 2014, when Tyler was 15, he was found to have a rare form of osteosarcoma in his arm and underwent treatments at Riley Hospital for Children in Indianapolis. But two years later, at the end of his senior year of high school, the disease reappeared in his pelvis. Despite another surgery as well as chemotherapy, he resolved to start as a freshman at Purdue University.

Bald and on crutches, he entered Purdue with a presidential scholarship and soon became a Boilermaker football superfan as he coped with life-threatening complications caused by yet another recurrence in his spine. He was at death’s door a few days before he attended the Purdue football game against Ohio State that he correctly predicted would result in an upset Boilermaker victory and his being named honorary team captain for a game played in one of the holiday bowls. At Purdue today, an undergraduate scholarship and a student gate at the football stadium memorialize his name.

One of Tyler’s doctors, Dr. Jamie Renbarger, currently heads Riley’s Center for Cancer and Blood Disorders and the Pediatric Precision Genomics Program, which serves children with aggressive solid tumors, high risk leukemias, and relapsed cancers, all of which are associated with poor outcomes. In consultation with a child’s oncologist and with a team of scientists, Dr. Renbarger uses genetic testing to identify DNA, RNA and proteins in cancer cells that can be targeted with different treatment options specific to the child’s needs.

According to Dr. Renbarger, “in about 85 to 90 percent of cases, we’ve found something clinically relevant about the patient or the tumor as a result of testing to help further guide therapy.” Dr. Renbarger is drawn to targeted therapies because they “may have fewer side effects than previous treatments, helping the child have a better quality of life and improving survival rates.”

Her optimism has been buoyed by the breakthrough of a colleague, Karen E. Pollok, who has used the cancer cells donated by Tyler Trent — they are called TT2 — to find a combination of drugs that substantially retards tumor growth. The donors of tumor samples are generally kept anonymous, but Tyler’s parents wanted to continue honoring his activism.

Dr. Pollok, who along with Dr. Renbarger visited Tyler two weeks before he died, was inspired by the meeting: “He was busily answering texts, tweets and managing Facebook to fulfill his last mission: to raise awareness for pediatric cancer research.” Today, Dr. Pollok adds, “our lab-quote when we discuss the research using Tyler’s cells is, ‘We will never give up!’” At the start of the coronavirus pandemic, her work on Tyler’s tumor models was deemed essential. She and colleagues published research in August in the journal Cancers that demonstrated that a combination of drugs could block the growth of these aggressive cancers.

Even after Tyler suffered seizures, clogged kidney tubes, emergency operations, and fevers that landed him in hospice, he gave interviews and published essays that testified to his remarkable ability to continue expressing himself in his unique way. Though Tyler never entered full adulthood, he managed to sustain “his passion to do whatever he could, even in the midst of this crazy, horrible journey that he was on,” Dr. Renbarger says.

Children with cancer, whether or not they are cured, need to find ways to retain a sense of themselves while dealing with the deleterious side effects of cytotoxic treatments. Dr. Renbarger therefore helped to create the Karuna Precision Wellness Center, where she works with individuals during and after cancer treatments to optimize their long-term quality of life through personalized integrative and wellness plans. The areas of focus include physical functioning, mental health (cognitive and emotional), and nutrition.

Kids especially face post-therapy hurdles, Dr. Renbarger believes, for they may experience alienation from their peers, anxiety, attention deficits and cognitive disorders related to memory, mental processing and executive functioning. Reintegration into school can be challenging. Additionally, since children who have received treatment “age at a faster rate,” they can be “more susceptible to diseases associated with aging like strokes, diabetes, joint and heart problems.” In an outpatient clinic, Dr. Renbarger assembles multidisciplinary teams — specialists in cardiology, adolescent medicine and fertility as well as educational and vocational coaches — to see pediatric patients into the best possible adulthood.

A similar determination led Tyler to donate a portion of the proceeds from his book, “The Upset: Life (Sports), Death … and the Legacy We Leave in the Middle,” toward cancer research. Along with his co-author, John Driver, and others, he composed it when his entire body had surrendered to paralysis except for his right arm. The voices of his parents, brothers and spiritual advisers supplement his account and form a sort of chorus. What emerges is a multifaceted portrait of a deeply religious young man fully convinced that “There is always an opportunity to help heal others’ hurts.”

The Upset” underscores the conviction of Tyler’s parents that “when a child gets cancer, a family gets cancer” and extends his efforts to hasten that time when no family with cancer will be left behind.

Could a Small Test Screen People for Covid-19?

Could a Smell Test Screen People for Covid?

A new modeling study hints that odor-based screens could quash outbreaks. But some experts are skeptical it would work in the real world.

A health worker in Altos de San Lorenzo, a neighborhood outside Buenos Aires, Argentina, administered a smell test last year.
A health worker in Altos de San Lorenzo, a neighborhood outside Buenos Aires, Argentina, administered a smell test last year.Credit…Alejandro Pagni/Agence France-Presse — Getty Images
Katherine J. Wu

  • Jan. 19, 2021, 5:49 p.m. ET

In a perfect world, the entrance to every office, restaurant and school would offer a coronavirus test — one with absolute accuracy, and able to instantly determine who was virus-free and safe to admit and who, positively infected, should be turned away.

That reality does not exist. But as the nation struggles to regain a semblance of normal life amid the uncontrolled spread of the virus, some scientists think that a quick test consisting of little more than a stinky strip of paper might at least get us close.

The test does not look for the virus itself, nor can it diagnose disease. Rather, it screens for one of Covid-19’s trademark signs: the loss of the sense of smell. Since last spring, many researchers have come to recognize the symptom, which is also known as anosmia, as one of the best indicators of an ongoing coronavirus infection, capable of identifying even people who don’t otherwise feel sick.

A smell test cannot flag people who contract the coronavirus and never develop any symptoms at all. But in a study that has not yet been published in a scientific journal, a mathematical model showed that sniff-based tests, if administered sufficiently widely and frequently, might detect enough cases to substantially drive transmission down.

Daniel Larremore, an epidemiologist at the University of Colorado, Boulder, and the study’s lead author, stressed that his team’s work was still purely theoretical. Although some smell tests are already in use in clinical and research settings, the products tend to be expensive and laborious to use and are not widely available. And in the context of the pandemic, there is not yet real-world data to support the effectiveness of smell tests as a frequent screen for the coronavirus. Given the many testing woes that have stymied pandemic control efforts so far, some experts have been doubtful that smell tests could be distributed widely enough, or made sufficiently cheat-proof, to reduce the spread of infection.

“I have been intimately involved in pushing to get loss of smell recognized as a symptom of Covid from the beginning,” said Dr. Claire Hopkins, an ear, nose and throat surgeon at Guy’s and St. Thomas’ Hospitals in the United Kingdom and an author of a recent commentary on the subject in The Lancet. “But I just don’t see any value as a screening test.”

A reliable smell test offers many potential benefits. It could catch far more cases than fever checks, which have largely flopped as screening tools for Covid-19. Studies have found that about 50 to 90 percent of people who test positive for the coronavirus experience some degree of measurable smell loss, a result of the virus wreaking havoc when it invades cells in the airway.

“It’s really like a function of the virus being in the nose at this exact moment,” said Danielle Reed, the associate director of the Monell Chemical Senses Center in Philadelphia. “It complements so much of the information you get from other tests.” Last month, Dr. Reed and her colleagues at Monell posted a study, which has not yet been published in a scientific journal, describing a rapid smell test that might be able to screen for Covid-19.

In contrast, only a minority of people with Covid-19 end up spiking a temperature. Fevers also tend to be fleeting, while anosmia can linger for many days.

A coronavirus testing site in Los Angeles. Smell tests, unlike P.C.R. and antigen tests, would not diagnose the disease nor look for the virus directly.
A coronavirus testing site in Los Angeles. Smell tests, unlike P.C.R. and antigen tests, would not diagnose the disease nor look for the virus directly.Credit…Kendrick Brinson for The New York Times

A smell test could also come with an appealingly low price tag, perhaps as low as 50 cents per card, said Derek Toomre, a cell biologist at Yale University and an author on Dr. Larremore’s paper. Dr. Toomre hopes that his version will fit the bill. The test, the U-Smell-It test, is a small smorgasbord of scratch-and-sniff scents arrayed on paper cards. People taking the test pick away at wells of smells, inhale and punch their guess into a smartphone app, shooting to correctly guess at least three of the five odors. Different cards contain different combinations of scents, so there is no answer key to memorize.

He estimated that the test could be taken in less than a minute. It is also a manufacturer’s dream, he said: A single printer “could produce 50 million of these tests per day.” Numbers like that, he argued, could make an enormous dent in a country hampered by widespread lack of access to tests that look directly for pieces of the coronavirus.

In their study, Dr. Larremore, Dr. Toomre and their collaborator Roy Parker, a biochemist at the University of Colorado, Boulder, modeled such a scenario using computational tools. Administered daily or almost daily, a smell screen that caught at least 50 percent of new infections was able to quash outbreaks nearly as well as a more accurate, slower laboratory test given just once a week.

Such tests, Dr. Larremore said, could work as a point-of-entry screen on college campuses or in offices, perhaps in combination with a rapid virus test. There might even be a place for them in the home, if researchers can find a way to minimize misuse.

“I think this is spot on,” said Dr. Carol Yan, an ear, nose and throat specialist at the University of California, San Diego. “Testing people repeatedly is going to be a valuable portion of this.”

Dr. Toomre is now seeking an emergency use authorization for the U-Smell-It from the Food and Drug Administration, and has partnered with a number of groups in Europe and elsewhere to trial the test under real-world conditions.

Translating theory into practice, however, will come with many challenges. Smell tests that can reliably identify people who have the coronavirus, while excluding people who are sick with something else, are not yet widely available. (Dr. Hopkins pointed to a couple of smell tests, developed before the pandemic, that cost about $30 each and remain in limited supply.) Should they ever be rolled out in bulk, they would inevitably miss some infected people and, unlike tests that look for the actual virus, could never diagnose disease on their own.

And smell loss, like fever, is not exclusive to Covid-19. Other infections can blunt a person’s sense of smell. So can allergies, nasal congestion from the common cold, or simply the process of aging. About 80 percent of people over the age of 75 have some degree of smell loss. Some people are born anosmic.

Moreover, in many cases of Covid-19, smell loss can linger long after the virus is gone and people are no longer contagious — a complication that could land some people in a post-Covid purgatory if they are forced to rely on smell screens to resume activity, Dr. Yan said.

There are also many ways to design a smell-based screen. Odors linked to foods that are popular in some countries but not others, such as bubble gum or licorice, might skew test results for some individuals. People who have grown up in highly urban areas might not readily recognize scents from nature, like pine or fresh-cut grass.

Smell also is not a binary sense, strictly on or off. Dr. Reed advocated a step in which test takers rate the intensity of a test’s odors — an acknowledgment that the coronavirus can drastically reduce the sense of smell but not eliminate it.

But the more complicated the test, the more difficult it would be to manufacture and deploy speedily. And no test, even a perfectly designed one, would function with 100 percent accuracy.

Dr. Ameet Kini, a pathologist at Loyola University Medical Center, pointed out that smell tests would also not be free of the problems associated with other types of tests, such as poor compliance or a refusal to isolate.

Smell screens are “probably better than nothing,” Dr. Kini said. “But no test is going to stop the pandemic in its tracks unless it’s combined with other measures.”

Could a Smell Test Screen People for Covid?

Could a Smell Test Screen People for Covid?

A new modeling study hints that odor-based screens could quash outbreaks. But some experts are skeptical it would work in the real world.

A health worker in Altos de San Lorenzo, a neighborhood outside Buenos Aires, Argentina, administered a smell test last year.
A health worker in Altos de San Lorenzo, a neighborhood outside Buenos Aires, Argentina, administered a smell test last year.Credit…Alejandro Pagni/Agence France-Presse — Getty Images
Katherine J. Wu

  • Jan. 19, 2021, 5:49 p.m. ET

In a perfect world, the entrance to every office, restaurant and school would offer a coronavirus test — one with absolute accuracy, and able to instantly determine who was virus-free and safe to admit and who, positively infected, should be turned away.

That reality does not exist. But as the nation struggles to regain a semblance of normal life amid the uncontrolled spread of the virus, some scientists think that a quick test consisting of little more than a stinky strip of paper might at least get us close.

The test does not look for the virus itself, nor can it diagnose disease. Rather, it screens for one of Covid-19’s trademark signs: the loss of the sense of smell. Since last spring, many researchers have come to recognize the symptom, which is also known as anosmia, as one of the best indicators of an ongoing coronavirus infection, capable of identifying even people who don’t otherwise feel sick.

A smell test cannot flag people who contract the coronavirus and never develop any symptoms at all. But in a study that has not yet been published in a scientific journal, a mathematical model showed that sniff-based tests, if administered sufficiently widely and frequently, might detect enough cases to substantially drive transmission down.

Daniel Larremore, an epidemiologist at the University of Colorado, Boulder, and the study’s lead author, stressed that his team’s work was still purely theoretical. Although some smell tests are already in use in clinical and research settings, the products tend to be expensive and laborious to use and are not widely available. And in the context of the pandemic, there is not yet real-world data to support the effectiveness of smell tests as a frequent screen for the coronavirus. Given the many testing woes that have stymied pandemic control efforts so far, some experts have been doubtful that smell tests could be distributed widely enough, or made sufficiently cheat-proof, to reduce the spread of infection.

“I have been intimately involved in pushing to get loss of smell recognized as a symptom of Covid from the beginning,” said Dr. Claire Hopkins, an ear, nose and throat surgeon at Guy’s and St. Thomas’ Hospitals in the United Kingdom and an author of a recent commentary on the subject in The Lancet. “But I just don’t see any value as a screening test.”

A reliable smell test offers many potential benefits. It could catch far more cases than fever checks, which have largely flopped as screening tools for Covid-19. Studies have found that about 50 to 90 percent of people who test positive for the coronavirus experience some degree of measurable smell loss, a result of the virus wreaking havoc when it invades cells in the airway.

“It’s really like a function of the virus being in the nose at this exact moment,” said Danielle Reed, the associate director of the Monell Chemical Senses Center in Philadelphia. “It complements so much of the information you get from other tests.” Last month, Dr. Reed and her colleagues at Monell posted a study, which has not yet been published in a scientific journal, describing a rapid smell test that might be able to screen for Covid-19.

In contrast, only a minority of people with Covid-19 end up spiking a temperature. Fevers also tend to be fleeting, while anosmia can linger for many days.

A coronavirus testing site in Los Angeles. Smell tests, unlike P.C.R. and antigen tests, would not diagnose the disease nor look for the virus directly.
A coronavirus testing site in Los Angeles. Smell tests, unlike P.C.R. and antigen tests, would not diagnose the disease nor look for the virus directly.Credit…Kendrick Brinson for The New York Times

A smell test could also come with an appealingly low price tag, perhaps as low as 50 cents per card, said Derek Toomre, a cell biologist at Yale University and an author on Dr. Larremore’s paper. Dr. Toomre hopes that his version will fit the bill. The test, the U-Smell-It test, is a small smorgasbord of scratch-and-sniff scents arrayed on paper cards. People taking the test pick away at wells of smells, inhale and punch their guess into a smartphone app, shooting to correctly guess at least three of the five odors. Different cards contain different combinations of scents, so there is no answer key to memorize.

He estimated that the test could be taken in less than a minute. It is also a manufacturer’s dream, he said: A single printer “could produce 50 million of these tests per day.” Numbers like that, he argued, could make an enormous dent in a country hampered by widespread lack of access to tests that look directly for pieces of the coronavirus.

In their study, Dr. Larremore, Dr. Toomre and their collaborator Roy Parker, a biochemist at the University of Colorado, Boulder, modeled such a scenario using computational tools. Administered daily or almost daily, a smell screen that caught at least 50 percent of new infections was able to quash outbreaks nearly as well as a more accurate, slower laboratory test given just once a week.

Such tests, Dr. Larremore said, could work as a point-of-entry screen on college campuses or in offices, perhaps in combination with a rapid virus test. There might even be a place for them in the home, if researchers can find a way to minimize misuse.

“I think this is spot on,” said Dr. Carol Yan, an ear, nose and throat specialist at the University of California, San Diego. “Testing people repeatedly is going to be a valuable portion of this.”

Dr. Toomre is now seeking an emergency use authorization for the U-Smell-It from the Food and Drug Administration, and has partnered with a number of groups in Europe and elsewhere to trial the test under real-world conditions.

Translating theory into practice, however, will come with many challenges. Smell tests that can reliably identify people who have the coronavirus, while excluding people who are sick with something else, are not yet widely available. (Dr. Hopkins pointed to a couple of smell tests, developed before the pandemic, that cost about $30 each and remain in limited supply.) Should they ever be rolled out in bulk, they would inevitably miss some infected people and, unlike tests that look for the actual virus, could never diagnose disease on their own.

And smell loss, like fever, is not exclusive to Covid-19. Other infections can blunt a person’s sense of smell. So can allergies, nasal congestion from the common cold, or simply the process of aging. About 80 percent of people over the age of 75 have some degree of smell loss. Some people are born anosmic.

Moreover, in many cases of Covid-19, smell loss can linger long after the virus is gone and people are no longer contagious — a complication that could land some people in a post-Covid purgatory if they are forced to rely on smell screens to resume activity, Dr. Yan said.

There are also many ways to design a smell-based screen. Odors linked to foods that are popular in some countries but not others, such as bubble gum or licorice, might skew test results for some individuals. People who have grown up in highly urban areas might not readily recognize scents from nature, like pine or fresh-cut grass.

Smell also is not a binary sense, strictly on or off. Dr. Reed advocated a step in which test takers rate the intensity of a test’s odors — an acknowledgment that the coronavirus can drastically reduce the sense of smell but not eliminate it.

But the more complicated the test, the more difficult it would be to manufacture and deploy speedily. And no test, even a perfectly designed one, would function with 100 percent accuracy.

Dr. Ameet Kini, a pathologist at Loyola University Medical Center, pointed out that smell tests would also not be free of the problems associated with other types of tests, such as poor compliance or a refusal to isolate.

Smell screens are “probably better than nothing,” Dr. Kini said. “But no test is going to stop the pandemic in its tracks unless it’s combined with other measures.”

An 11-Minute Body-Weight Workout With Proven Fitness Benefits

Phys Ed

An 11-Minute Body-Weight Workout With Proven Fitness Benefits

Five minutes of burpees, jump squats and other calisthenics, alternating with rest, improved aerobic endurance in out-of-shape men and women.

Credit…Getty Images
Gretchen Reynolds

  • Jan. 13, 2021, 5:00 a.m. ET

Five minutes of burpees, jump squats and other calisthenics significantly improve aerobic endurance, according to one of the first randomized, controlled trials to test the effects of brief body-weight workouts. The study’s findings are predictable but reassuring, at a time when many of us are relying on short exercise sessions in our homes to gain or retain our fitness. They provide scientific assurance that these simple workouts will work, physiologically, and our burpees will not be in vain.

Last year, when the pandemic curtailed traditional gym hours and left many people hesitant to exercise outside on crowded sidewalks or paths, quite a few of us moved our workouts indoors, into our living rooms or basements, altering how we exercise. Some of us purchased stationary bicycles and started intense spin classes or turned to online personal trainers and yoga classes. But many of us started practicing some version of a body-weight routine, using calisthenics and other simple strength-training exercises that rely on our body weight to provide resistance.

Body-weight training has been a staple of exercise since almost time immemorial, of course. Usually organized as multiple, familiar calisthenics performed one after another, this type of exercise has gone by various names, from Swedish Exercises a century ago to the Royal Canadian Air Force’s Five Basic Exercises (5BX) program in the 1960s, to today’s Scientific 7-Minute Workout and its variations.

In general, one of the hallmarks of these programs is that you perform the exercises consecutively but not continuously; that is, you complete multiple repetitions of one exercise, pause and recover, then move on to the next. This approach makes the workouts a form of interval training, with bursts of intense exertion followed by brief periods of rest.

Traditional interval training has plenty of scientific backing, with piles of research showing that a few minutes — or even seconds — of strenuous intervals, repeated several times, can raise aerobic fitness substantially. But the exercise in these studies usually has involved stationary cycling or running.

Few experiments have examined the effects of brief body-weight workouts on endurance and strength, and those few had drawbacks. Most focused on people who already were fit, and almost none met the scientific gold standard of being randomized and including an inactive control group. Consequently, our faith in the benefits of short body-weight training may have been understandable, but evidence was lacking.

So, for the new study, which was published this month in the International Journal of Exercise Science, researchers at McMaster University in Hamilton, Ontario, and the Mayo Clinic in Rochester, Minn., decided to develop and test a basic body-weight routine. They modeled their version on the well-known 5BX program, which once had been used to train members of the Canadian military in remote posts. But the researchers swapped out elements from the original, which had included exercises like old-fashioned situps that are not considered particularly good for the back or effective in building endurance.

They wound up with a program that alternated one minute of calisthenics, including modified burpees (omitting the push-ups that some enthusiasts tack onto the move) and running in place, with a minute of walking, also in place. The routine required no equipment, little space and a grand total of 11 minutes, including a minute for warming up and cooling down.

They then recruited 20 healthy but out-of-shape young men and women, measured their current fitness, leg power and handgrip strength and randomly assigned half to start practicing the new program three times a week, while the others continued with their normal lives, as a control.

The exercisers were asked to “challenge” themselves during the calisthenics, completing as many of each exercise as they could in a minute, before walking in place, and then moving to the next exercise.

After six weeks, all of the volunteers returned to the lab for follow-up testing. And, to no one’s surprise, the exercisers were more fit, having upped their endurance by about 7 percent, on average. Their leg power also had grown slightly. The control group’s fitness and strength remained unchanged.

“It was good to see our expectations confirmed,” says Martin Gibala, a professor of kinesiology at McMaster University, who oversaw the new study and, with various collaborators, has published influential studies of intense interval training in the past.

“It seemed obvious” that this kind of training should be effective, he says. But “we now have evidence” that brief, basic body-weight training “can make a meaningful difference” in fitness, he says.

The study was small and quite short-term, though, and looked at the effects only among healthy young people who are capable of performing burpees and jump squats. “Some people may need to substitute” some of the exercises, Dr. Gibala says, especially anyone who has problems with joint pain or balance. (See the Standing 7-Minute Workout for examples of appropriate replacements, in that case.)

But whatever mix of calisthenics you settle on, “the key is to push yourself a bit” during each one-minute interval, he says.

Here is the full 11-minute workout used in the study, with video links of each exercise by Linda Archila, a researcher who led the experiment while a student at McMaster University.

  • 1 minute of easy jumping jacks, to warm up

  • 1 minute of modified burpees (without push-ups)

  • 1 minute of walking in place

  • 1 minute of high-knee running in place

  • 1 minute of walking in place

  • 1 minute of split squat jumps (starting and ending in the lunge position, while alternating which leg lands forward)

  • 1 minute of walking in place

  • 1 minute of high-knee running in place

  • 1 minute of walking in place

  • 1 minute of squat jumps

  • 1 minute of walking in place, to cool down

How the Right Foods May Lead to a Healthier Gut, and Better Health

How the Right Foods May Lead to a Healthier Gut, and Better Health

A diet full of highly processed foods with added sugars and salt promoted gut microbes linked to obesity, heart disease and diabetes.

Credit…Getty Images
Anahad O’Connor

  • Jan. 11, 2021, 11:00 a.m. ET

Scientists know that the trillions of bacteria and other microbes that live in our guts play an important role in health, influencing our risk of developing obesity, heart disease, Type 2 diabetes and a wide range of other conditions. But now a large new international study has found that the composition of these microorganisms, collectively known as our microbiomes, is largely shaped by what we eat.

By analyzing the diets, health and microbiomes of more than a thousand people, researchers found that a diet rich in nutrient-dense, whole foods supported the growth of beneficial microbes that promoted good health. But eating a diet full of highly processed foods with added sugars, salt and other additives had the opposite effect, promoting gut microbes that were linked to worse cardiovascular and metabolic health.

The researchers found that what people ate had a more powerful impact on the makeup of their microbiomes than their genes. They also discovered that a variety of plant and animal foods were linked to a more favorable microbiome.

One critical factor was whether people ate foods that were highly processed or not. People who tended to eat minimally processed foods like vegetables, nuts, eggs and seafood were more likely to harbor beneficial gut bacteria. Consuming large amounts of juices, sweetened beverages, white bread, refined grains, and processed meats, on the other hand, was associated with microbes linked to poor metabolic health.

“It goes back to the age-old message of eating as many whole and unprocessed foods as possible,” said Dr. Sarah E. Berry, a nutrition scientist at King’s College London and a co-author of the new study, which was published Monday in Nature Medicine. “What this research shows for the first time is the link between the quality of the food we’re eating, the quality of our microbiomes and ultimately our health outcomes.”

The findings could one day help doctors and nutritionists prevent or perhaps even treat some diet-related diseases, allowing them to prescribe personalized diets to people based on the unique makeup of their microbiomes and other factors.

Many studies suggest that there is no one-size-fits-all diet that works for everyone. The new study, for example, found that while some foods were generally better for health than others, different people could have wildly different metabolic responses to the same foods, mediated in part by the kinds of microbes residing in their guts.

“What we found in our study was that the same diet in two different individuals does not lead to the same microbiome, and it does not lead to the same metabolic response,” said Dr. Andrew T. Chan, a co-author of the study and a professor of medicine at Harvard Medical School and Massachusetts General Hospital. “There is a lot of variation.”

The new findings stem from an international study of personalized nutrition called Predict, which is the world’s largest research project designed to look at individual responses to food. Started in 2018 by the British epidemiologist Tim Spector, the study has followed over 1,100 mostly healthy adults in the United States and Britain, including hundreds of identical and nonidentical twins.

The researchers collected data on a wide range of factors that influence metabolism and disease risk. They analyzed the participants’ diets, microbiomes and body fat. They took blood samples before and after meals to look at their blood sugar, hormones, cholesterol and inflammation levels. They monitored their sleep and physical activity. And for two weeks they had them wear continuous glucose monitors that tracked their blood sugar responses to different meals.

The researchers were surprised to discover that genetics played only a minor role in shaping a person’s microbiome. Identical twins were found to share just 34 percent of the same gut microbes, while people who were unrelated shared about 30 percent of the same microbes. The composition of each person’s microbiome appeared instead to be driven more by what they ate, and the types of microbes in their guts played a strong role in their metabolic health.

The researchers identified clusters of so-called good gut bugs, which were more common in people who ate a diverse diet rich in high-fiber plants — like spinach, broccoli, tomatoes, nuts and seeds — as well as minimally processed animal foods such as fish and full-fat yogurt. They also found clusters of “bad” gut bugs that were common in people who regularly consumed foods that were highly processed. One common denominator among heavily processed foods is that they tend to contain very little fiber, a macronutrient that helps to nourish good microbes in the gut, the researchers said.

Among the “good” strains of gut microbes were Prevotella copri and Blastocystis, both of which were associated with lower levels of visceral fat, the kind that accumulates around internal organs and that increases the risk of heart disease. These microbes also appeared to improve blood sugar control, an indicator of diabetes risk. Other beneficial microbes were associated with reduced inflammation and lower spikes in blood fat and cholesterol levels after meals, all of which play a role in cardiovascular health.

The new study was funded and supported by Zoe Global, a health science company, as well as by the Wellcome Trust, a British nonprofit, and several public health groups.

Dr. Berry said the findings suggest that by looking at microbiome profiles they can identify people at high risk of developing metabolic diseases and intervene early on. She and her colleagues are now planning a clinical trial that will test whether telling people to change specific foods in their diets can alter levels of good and bad microbes in their guts and subsequently improve their health.

“We think there are lots of small changes that people can make that can have a big impact on their health that might be mediated through the microbiome,” she said.