Tag: Centers for Disease Control and Prevention

C.D.C. Panel Recommends Covid Booster Shots for Millions of Americans

Recipients of the Moderna and the J.&J. vaccines may receive extra doses, the committee said, although the shots continue to prevent illness and death.

The Hot New Back-to-School Accessory? An Air Quality Monitor

Parents are sneaking carbon dioxide monitors into their children’s schools to determine whether the buildings are safe.

What Parents Need to Know About the C.D.C.’s Covid School Guidelines

The agency’s advice on distancing, masks and vaccination bring the coming school year a bit more into focus.

Covid’s Delta Variant: What We Know

The variant is gaining traction worldwide. But vaccines are driving down coronavirus case numbers in the U.S., and it’s unclear whether Delta will reverse that trend.

The super-contagious Delta variant of the coronavirus is now responsible for about one in every five Covid-19 cases in the United States, and its prevalence has doubled in the last two weeks, heath officials said on Tuesday.

First identified in India, Delta is one of several “variants of concern,” as designated by the Centers for Disease Control and Prevention and the World Health Organization. It has spread rapidly through India and Britain.

Its appearance in the United States is not surprising. And with vaccinations ticking up and Covid-19 case numbers falling, it’s unclear how much of a problem Delta will cause here. Still, its swift rise has prompted concerns that it might jeopardize the nation’s progress in beating back the pandemic.

“The Delta variant is currently the greatest threat in the U.S. to our attempt to eliminate Covid-19,” Dr. Anthony S. Fauci, the nation’s leading infectious disease expert, said at the briefing. The good news, he said, is that the vaccines authorized in the United States work against the variant. “We have the tools,” he said. “So let’s use them, and crush the outbreak.”

Here are answers to some common questions about the Delta variant.

Why are people worried about the Delta variant?

Delta, formerly known as B.1.617.2, is believed to be the most transmissible variant yet, spreading more easily than both the original strain of the virus and the Alpha variant first identified in Britain. Public health officials there have said that Delta could be 50 percent more contagious than Alpha, though precise estimates of its infectiousness vary.

Other evidence suggests that the variant may be able to partially evade the antibodies made by the body after a coronavirus infection or vaccination. And the variant may also render certain monoclonal antibody treatments less effective, the C.D.C. notes.

Delta may also cause more severe illness. A recent Scottish study, for instance, found that people infected by the Delta variant were roughly twice as likely to be hospitalized than were those infected with Alpha. But uncertainties remain, scientists said.

“The severe disease piece I think is the one question that really hasn’t been answered yet,” said Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

Where is it spreading?

Delta has been reported in 80 countries. It is now the most common variant in India and Britain, where it accounts for more than 90 percent of cases.

Delta was first identified in the United States in March. Although Alpha remains the most prevalent variant here, Delta has spread quickly. In early April, Delta represented just 0.1 percent of cases in the United States, according to the C.D.C. By early May, the variant accounted for 1.3 percent of cases, and by early June, that figure had jumped to 9.5 percent. As of a few days ago, the estimate hit 20.6 percent, Dr. Fauci said at the briefing.

Joseph Prezioso/Agence France-Presse — Getty Images

If I’m vaccinated, do I need to worry?

The Delta variant is unlikely to pose much risk to people who have been fully vaccinated, experts said.

“If you’re fully vaccinated, I would largely not worry about it,” said Dr. Ashish K. Jha, dean of the Brown University School of Public Health.

According to one recent study, the Pfizer-BioNTech vaccine was 88 percent effective at protecting against symptomatic disease caused by Delta, nearly matching its 93 percent effectiveness against the Alpha variant. But a single dose of the vaccine was just 33 percent effective against Delta, the study found.

“Fully immunized individuals should do well with this new phase of the epidemic,” said Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine. “However, the protection offered by a single dose appears low, and of course if you are not at all vaccinated, consider yourself at high risk.”

Delta is likely to infect “large numbers” of unvaccinated people, he said.

Will it cause a new surge?

The pandemic is waning in the United States, with cases, hospitalizations and deaths all on the decline. The seven-day case average, roughly 10,350 a day, is the lowest since March 2020, Dr. Rochelle Walensky, director of the C.D.C., said at the briefing on Tuesday. “These numbers demonstrate the extraordinary progress we’ve made against a formidable foe,” she said.

So while Delta may account for an increasing percentage of cases, it is not yet clear whether it will drive the total number of cases higher.

“I think we are not going to see another big, national surge in the United States because we have enough vaccination to prevent that,” Dr. Osterholm said.

Still, vaccination rates have been highly uneven, and are lower in certain states and demographic groups. Delta could fuel outbreaks in the South, where vaccinations lag, or among young people, who are less likely to be vaccinated than their elders.

“In places where there’s still a lot of susceptibility to the virus, it opens a window for cases to start going up again,” said Justin Lessler, an infectious disease epidemiologist at Johns Hopkins University. “But even in those states, and certainly nationally, we’re probably not getting back to the numbers we were seeing last winter.”

Still, he said, it could prolong our path out of the pandemic. “It continues the doldrums,” he said.

What can I do?

Get vaccinated. If you’re already vaccinated, encourage your family, friends and neighbors to get vaccinated. Vaccination is likely to slow the spread of all the variants and reduce the odds that new, even more dangerous variants emerge.

“I encourage people who are vaccinated to trust in the vaccines but be cognizant that new variants will continue to occur where transmission exists,” said Saskia Popescu, an infectious disease epidemiologist at George Mason University. “So it’s really about ensuring local, national and global vaccination.”

What the C.E.O. of Pfizer and Other Covid-19 Fighters Learned From Their Parents

Various people working to stop the pandemic reflected on the life skills their parents taught them: determination, teamwork, resilience and more.

Debra Weiner interviewed people who are working to beat the coronavirus about the most valuable things their parents taught them. Following are excerpts from a few of those stories, edited and condensed.


Anything Is Possible

Albert Bourla Chairman and chief executive officer of Pfizer

Albert Bourla, third from left, at his wedding with, from left, his father-in-law, Jack Alchanati; his mother, Sara Bourla; his wife, Myriam Alchanati; his mother-in-law, Rachel Alchanati; his father, Mois Bourla. 
Albert Bourla, third from left, at his wedding with, from left, his father-in-law, Jack Alchanati; his mother, Sara Bourla; his wife, Myriam Alchanati; his mother-in-law, Rachel Alchanati; his father, Mois Bourla. via Albert Bourla

I was born in Thessaloniki, Greece. Before the Holocaust, there were 50,000 Jews there. About 95 percent were exterminated. A lot of survivors don’t discuss what happened to them. My family did. On Sundays, we would gather in the living room with the relatives. My sister and cousins and I would be sitting on the floor and we’d say: “Tell us a story about that time. Tell us a story.” And my mother would.

My mother was the youngest of seven children. She lived in hiding with her oldest sister for a year, starting in 1943. Like Anne Frank, my mom wasn’t supposed to go out of the house. But she was a teenager, didn’t follow all the rules, and one day when she was out, she was spotted and arrested and put in prison.

This was toward the end of the war and the Germans were no longer sending the Jews in Greece to Auschwitz. But as a prisoner, she was beaten and abused. And every day at noon, some of the prisoners would be taken to the other side of town and the next day executed. Her sister’s husband, who was quite wealthy, had paid a ransom to the commander of the Nazi occupation in Thessaloniki. So her sister thought my mother was secure. Still, each day she would go to the prison to see who was going out. And one day she saw my mom loaded into the truck. Her sister ran to tell her husband, who contacted the commander. “I gave you all this money. What’s this?”

He said, “I have no idea what you’re talking about. Let me see.”

My mother didn’t sleep at all that night. Someone told her to be brave but she just kept crying. At dawn, she and the others were lined up against a wall in front of a firing squad when at the last moment, a BMW motorbike with two German soldiers drove up. They handed some documents to the officer in charge and my mother and another woman were removed from the line. As they left to go back to the prison, she could hear the machine guns slaughtering the others.

My mother told us about everything in detail with the same easiness that I share childhood memories with my kids. She never said, “Look what the Germans did to me.” That was irrelevant. And she never said, “Oh, when I suffered.” She put a humorous spin on things so we didn’t feel the horror. And most important, the stories were filled with messages of optimism: “I was in worst position once, and now I have you and your sister. Life is miraculous. Nothing is impossible.”

That was the spirit of her. And she inspired me to be the same. In my first year of middle school, they told us there were going to be elections for class president, vice president and secretary. I asked my mom, “Do you think I should raise my hand?”

She said yes.

“But I’m the only Jew in the school.”

“Just do it. Go make your speech.”

And I was elected president.

My mother believed you can do anything in life. That there’s always a way. The way may not be clear in the beginning, but there is always a way. I owe her a lot because of that. She is my role model.


Listen to the Other Side

Dr. Soumya Swaminathan Chief scientist at the World Health Organization, known for her research on tuberculosis and H.I.V.

Soumya Swaminathan, far right, with her parents, Mina and MS Swaminathan, and her sisters, Nitya, front left, and Madhura, center.via Soumya Swaminathan

My father, MS Swaminathan, shot into prominence when he was very young. He collaborated with the Nobel Prize winner Norman Borlaug and developed new, high-yielding varieties of seeds for wheat and rice, and convinced farmers around Delhi and Punjab to grow them. Wheat production went up three or four times. From being a nation that had to import food grains from the United States, by the early 1970s, we were basically food secure. My father became known as the Father of the Green Revolution.

But at the peak of his career, there was an attack on his work by some of his closest colleagues about the unintended side-effects of improving the yields of plants. My father had himself recognized that because of the use of pesticides and fertilizers there would be some environmental damage and contamination of the water, and he had spoken about it. But there was a euphoria at the time that India had become food self-sufficient. It was immediate benefits versus long-term risks.

The criticism was in all the newspapers. Kids at school would ask, “Is what they said true? Did your father do these bad things?” And the atmosphere at home was somber. I remember asking my father, “Don’t you hate these people who write all these nasty things about you?”

“No, no, no. I don’t hate them,” he said. “There’s no point in being angry. It’s their right to question and write what they want. If you believe in something and think you are doing the right thing, then even if people criticize you, you carry on. It can seem unfair, but there could also be some something you can take from it, some element you didn’t do right or didn’t communicate in the right way that you can try to improve on.”

My father was a problem solver and he did it by listening to the people who were most affected by the problem. On weekends or holidays, my sisters and I, and sometimes our family’s gardener’s kids, would often go with him to the farming villages. While we were running around in the sugar cane and wheat fields playing hide and seek, he would sit with the farmers and hear how they were doing with the new seeds and if they were having any problems, and be open to changing course if needed. He would always say to the farmers, “This will only be a success story if it works for you.”

As a young tuberculosis researcher, I went into a remote tribal community in south India to explain why it’s very important to identify and treat people with TB early. People in the tribe said to me: “Maybe once in two years somebody in our village gets diagnosed with TB. Our people die of other infectious diseases. Children die from diarrhea. Somebody falls in the forest, fractures their leg and we have to carry that person 15 kilometers to a health center where most often there’s no surgeon so nothing can be done. These are our day-to-day problems, so it doesn’t seem appropriate that you’re discussing TB but aren’t trying to solve our other issues.” I thought then of my childhood and what I saw my father do. He knew that you needed to look holistically at people’s physical, social and economic environment and see through their eyes.

When I am in a situation where I’m in disagreement or have a completely different view, I may feel at the moment quite upset. But when I reflect further or have a discussion and try to understand where the other person is coming from, I start to say, “OK, this is why they are so negative or angry.” And that is when you start getting solutions.


Fierce Determination

Michelle Gaskill-Hames Senior vice president for hospital and health plan operations for Kaiser Permanente’s Northern California region

Michelle Gaskill-Hames with her father, Ivan Gaskill.via Michelle Gaskill-Hames

My parents were born and raised in the same working-class neighborhood in Detroit. They played together as kids, dated in high school, then both went to Wayne State University. My mother majored in special education. My father had a math and computer science degree and was selected for a management training program at Michigan Bell, which was unusual for a young African-American in the early 1960s. Then, within less than a year of getting married, he was driving home from work and a car went through a red light and slammed into his.

His car was literally wrapped around a tree. They saved his life, but he was left paralyzed from the waist down with limited upper body movement. He was classified as a quadriplegic. He was 23. My mother was 22.

Back in that day, many quadriplegics gave up. That was never my father’s story. He wasn’t going to let the accident determine his life. He was ambitious. He had goals. And with my mother right there with him, nothing was going to deter him from returning to work, getting a house and adopting me. It’s funny. Some people might think having a father who was a quadriplegic is not a blessing. But to have parents who lived with such determination was the best blessing I could have ever had.

As a child, I thought it was cool that he had an electric wheelchair. I’d ride on his lap through the neighborhood to go get ice cream. When I got bigger, I’d ride my bike and he’d zoom along with me. I didn’t realize that people with disabilities could be discriminated against until we were at a restaurant once when the waiter came to the table, looked at my mother and said, “What would he like to order?”

My father didn’t raise his voice. He didn’t bat an eye. He just said, “Well, I will have the prime rib, medium-rare, horseradish on the side,” and made it very clear that his disability was not in any way connected to his mind.

That was my first recognition that people might feel sorry for my father or look down on him in some way. But I never did. And my dad never showed any sign of self-pity. He believed there was nothing you couldn’t do if you were focused and determined.

It’s not that there weren’t obstacles, but he believed that obstacles were meant to be overcome.

When I was in sixth grade, there was an oratory contest. Everyone had to recite a poem or speech. I thought I’d do the “I Have a Dream” speech. But my father said, “No, everybody is going to do that,” and he suggested the poem “If” by Rudyard Kipling.

It’s been my mantra ever since. I have a framed copy of it at work, right behind my desk. Whenever I’m dealing with a stressful situation, I turn around and read it. Even if I just get through the first lines: If you can keep your head when all about you / Are losing theirs and blaming it on you / If you can trust yourself when all men doubt you / But make allowance for their doubting too; I’m like, “OK. Got it. I can do this.” Not just because the words of the poem instill confidence, but because my father taught it to me. He was my hero. In my mind, he was 7 feet tall.



Ilona Bartnik Critical care nurse, University of Chicago Medical Center

Ilona Bartnik as a baby with, from left, her grandmother Jozefa Bartnik; her mother, Renata Bartnik, and her father, Krzysztof Bartnik.via Ilona Bartnik

I came to Chicago from Poland in 2002. My first day in school someone gave me a list of my classes and room numbers, but I didn’t know which way to go. I didn’t know who to ask or how to ask, because I spoke then a very broken English. I was afraid people wouldn’t understand me or that I wouldn’t understand them, and then they’d make fun of me.

Especially in the beginning, I’d come home from school crying. Not because anyone had been mean, but because I was overwhelmed. My parents helped as much as they could. They’d say the typical things you tell a 17-year-old girl: “Oh, it’ll get better. You’ll make new friends.” Then they would make me my favorite meal — pierogies with strawberries or blueberries.

But I would say: “I miss my old friends. I wish we could go back to Poland. I don’t know what we’re even doing here.”

There, my mom owned a small grocery store. Everyone in our town knew us. Here, my mom was a cleaning lady. It was embarrassing. Later my mom studied to become a dialysis technician. She would work long hours then go to school. On one hand, OK, now I don’t have to say she cleans houses. But then I never got to see her much because she was so busy.

But if it was hard for me to basically learn everything again, for my parents it was much harder. Learning a new language, getting a house in a good area, applying for a loan, even going to a grocery store, all of that was complicated. I’d hear them talking to their Polish friends who’d been here longer about which neighborhoods had good schools. Then they’d do the math to see what they could afford and get an extra job on the side just to make sure.

So they did whatever they needed to do to support us. But culture-wise, they were not as adaptable. They’d introduce me to the kids of their Polish friends, but my closest friends were other nationalities: Russian, Hispanic, Bulgarian, German. My parents were nice to them in their presence, but given Polish history there is a bit of tension between Polish and Germans, and Polish and Russians. And later it was always like, “Why don’t you just hang out with your own people” kind of thing. They didn’t understand that you can be a different color and still share the same things.

Maybe my parents preferred their own culture because it reminded them of home. Or because it felt like the one piece in their lives that they could control. But because my parents moved us here, I went from “I don’t want to change” to “I don’t want to stay the same.” I like trying new things.

This last year has been rough. Rules at the hospital changed so fast and so much. One week it was this; the next week it was that. Everyone was stressed out. But because of what I had to go through in experiencing a totally different culture, I knew I could adapt. I knew I was resilient. I knew I’d be able to cope.


Personal Connection

Dr. Anne Schuchat Principal deputy director of the Centers for Disease Control and Prevention, retiring this month

Anne Schuchat, center, with her parents, Molly and Michael Schuchat.via Anne Schuchat

A lot of people are upset when they see bad things happening in the world. But my parents said, “What can we do about it?” When the Russians invaded Hungary in 1956, my parents, who’d only been married three years, had two kids and were expecting a third, opened their home for several months to a Hungarian refugee family that had escaped. Later, with others from her synagogue, my mom helped set up the Anne Frank House, a residence for homeless women in Washington.

I wouldn’t say they were activists, but life was about connecting with people and our home was a gathering place. After having five kids in seven years, my mom went back to school to get her Ph.D. in anthropology, and she would host the department parties. This was in the ’60s, so you can imagine what her classmates were like. Later my mom became interested in China and got involved with the U.S. China Peoples Friendship Association, and all these folks who had lived there in the 1930s or ’40s, would come to our house for meetings. And Passover Seders were an event. We’d have almost 40 people both nights, and not just extended family. There’d be Jews and non-Jews, friends from school who’d never been to a Seder, my mom’s professors, people visiting from other countries.

Bringing people together was part of my mom’s route to happiness, and that’s maybe why I try to turn whatever community I’m with into a welcoming environment. At the C.D.C., we have these two-year trainings for epidemic intelligence service officers. When I was branch chief, I remembered how in my mom’s office there was this fake certificate from a behavioral services organization she worked for that read, “This officially honors Molly Schuchat,” then said all these silly things. So I started making these personal little collages for the officers when they graduated. For the person who did nose swabs on 4,000 people, the border was lots of little noses. The one who’d negotiated lots of complicated relationships between institutions got the World Peace award.

In 2014, I was asked to lead this trial of an experimental Ebola vaccine in Sierra Leone. It was in the middle of an epidemic, working with counterparts who had lost friends to this virus. At times it seemed totally hopeless and unsolvable. Everybody was exhausted, hitting walls and a little bit scared. Somebody earlier had given me pompoms, so I pulled them out and went, “OK, we can get through this; this is what we’re going to do next,” and tried to help our team see that what they were doing was really brave, and that they were making a difference.

Public health can’t just be about the results because for every problem you solve, there are 10 more you have to tackle. It’s Sisyphean work. I’ve been lucky to be part of many things that have had a positive impact on the world. But as I moved into more senior positions, it was the warmth and connection I felt with the people I worked with that has given me joy. As my mom once said, “It doesn’t count if you don’t share it.”

Reports of Severe Covid or Death After Vaccination Are Rare, but Not Unexpected

No vaccine is ever 100 percent effective, experts say, stressing that the shots remain critical in reducing severe disease and death from the coronavirus.

Over the last few months, a steady drumbeat of headlines has highlighted the astounding real-world effectiveness of the Covid-19 vaccines, especially the mRNA vaccines made by Pfizer-BioNTech and Moderna. The vaccines, study after study has shown, are more than 90 percent effective at preventing the worst outcomes, including hospitalization and death.

But alongside this good news have been rare reports of severe Covid in people who had been fully vaccinated.

On June 3, for instance, Napa County announced that a fully vaccinated woman, who was more than a month past her second Moderna shot, had died after being hospitalized with Covid. The woman, who was over 65 and had underlying medical conditions, had tested positive for the Alpha variant, which was first identified in Britain.

Although these cases are tragic, they are uncommon — and not unexpected.

“I’m very sad that she had a sufficiently severe illness that it actually led to her death,” said Dr. William Schaffner, medical director of the National Foundation for Infectious Diseases and a vaccine expert at Vanderbilt University. But, he noted, “we expected to have the occasional breakthrough infection.”

Such cases should not dissuade people from getting vaccinated, scientists said. “There is not a vaccine in history that has ever been 100 percent effective,” said Dr. Paul Offit, the director of the Vaccine Education Center at Children’s Hospital of Philadelphia. “This is your best chance of avoiding severe, critical disease. But as is true of everything in medicine, it’s not perfect.”

Severe Covid is rare in people who have been fully vaccinated. In a paper published last month, the Centers for Disease Control and Prevention said that it had received reports of 10,262 breakthrough infections by April 30. That is just a tiny fraction of the 101 million Americans who had been vaccinated by that date, though the agency noted that it likely represented “a substantial undercount” of breakthrough infections.

Of those breakthrough cases, 10 percent of patients were hospitalized and 2 percent died — and in some of those cases, patients were hospitalized or died from something unrelated to Covid-19. The median age of those who died was 82.

Older adults, who are at greater risk for Covid complications, may also be more likely to develop breakthrough infections because they are known to mount weaker immune responses to vaccines. People who are immunocompromised or have other chronic health conditions may also be at increased risk.

Some of the variants — particularly Beta, which was first identified in South Africa — may be more likely to evade the protection induced by vaccines. But Beta is not currently common in the United States, Dr. Schaffner noted.

The Alpha variant that infected the Napa County woman is highly contagious, but vaccines provide good protection against it — as well as against the original strain of the virus.

“Vaccines provide exceptional protection against death and illness from the virus and all residents should continue to get vaccinated to protect themselves and others,” Dr. Karen Relucio, Napa County’s public health officer, said in a statement.

Breakthrough infections are likely to decrease as more people get vaccinated and community transmission rates fall. “The virus will find fewer and fewer people to infect — it will be harder for the virus to work its way through the population,” Dr. Schaffner said. “These are great vaccines. In order for the vaccines to work optimally — on an individual basis and a community basis — as many people as possible have to be vaccinated.”

So, You Want to Mingle Outdoors This Summer?

Going to Disney World this summer? Or to your niece’s sixth birthday party? Here’s how to do it safely.

During spring break last month, Monica Gandhi tested her confidence in coronavirus science. She and her two unvaccinated children stood in a packed crowd near a well-known bridge in Austin, Texas, to enjoy watching the emergence at dusk of thousands of Brazilian free-tailed bats.

No one in the group but she and her kids were wearing masks; the state had lifted its mask mandate in early March. But Dr. Gandhi, an infectious diseases physician and professor of medicine at the University of California, San Francisco, had read studies showing it is rare for people to transmit the coronavirus outdoors. And she knew that the regional infection rate was low. So, she decided to take off her mask, as well as those on her 11- and 13-year-old children.

“I was really nervous, but I did it,” she said. “You’ve just got to do it.” Neither Dr. Gandhi, who was vaccinated, nor her children got sick in the coming weeks.

Dr. Gandhi is one of many health experts encouraging Americans to embrace the outdoors as they make plans for their second summer of the pandemic. The outdoor transmission rate for the coronavirus is very low, and much lower than the indoor rate, several lines of evidence suggest.

A study in Wuhan, China, last year identified only one case of outdoor transmission (the case is thought to have resulted from a conversation between two people, both of whom became infected) among 7,324 infections. In figures released by health authorities by health authorities in Ireland, only one in 1,000 coronavirus infections was traced to outdoor transmission.

But it’s a bit of an art form to apply those findings to specific outdoor activities this summer, especially at full capacity venues and in the context of each individual’s risk for Covid-19. For instance, how should vaccinated parents of an unvaccinated child consider the myriad scenarios and risks associated with, say, a major-league baseball game in San Diego, an outdoor concert at Tanglewood in Massachusetts or the backyard birthday party of a neighborhood friend?

Finding Hard Numbers

Some experts, including Dr. Gandhi, advise people considering outdoor options to lean heavily on local coronavirus infection rates, Covid-19 hospitalization statistics or vaccination rates. But other public-health and infectious-disease experts continue to advocate for even more nuanced and individualized calculations that are sensitive to the size and density of crowds, airflow and health factors, such as your vaccination status and the overall strength of your immune system.

Dr. Gandhi hopes that people making summer plans look at local public-health numbers that can be found at online coronavirus data dashboards, like she did for her Austin trip. Federal officials have not clearly stated a numerical threshold of daily average cases or Covid-19 hospitalizations to use in making risk assessments, but Dr. Gandhi and two colleagues sketched a framework in an essay published last month.

They advised pegging an end to masking and distancing restrictions to Covid-19 hospitalization rates of fewer than five daily cases (meaning infections) per 100,000, averaged over several days.

“I think you could do something like three cases per 100,000 or two hospitalizations per 100,000,” Dr. Gandhi said. “You need to come up with a metric and say it’s safe to unmask outdoors even in crowded settings.”

Peter Chin-Hong, a medical professor and infectious-disease expert at the University of California, San Francisco, pointed to an average daily case rate of two per 100,000 people as a threshold for considering outdoor travel destinations.

“Travelers should look at Covid-19 burden in the proposed destination like they do the weather report,” he said, adding that these data are most relevant for people who are unvaccinated or have suppressed immune systems. The local vaccination rate might be the most telling figure on regional coronavirus dashboards, Dr. Chin-Hong said, because it affects infections and other Covid-19 metrics. Coronavirus infections started to drop this year in California and Israel when the percentage of vaccinated adults reached about 50 percent, he said, suggesting that figure as a threshold.

Mask Safety and Signals

Vaccination is a bottom line for all mingling considerations, including those outdoors, said Gregg Gonsalves, an epidemiologist at the Yale School of Public Health. “If you’re vaccinated, it’s really hard to think of a reason to dissuade you from outdoor activities this summer, even crowded ones, say a big wedding, if everyone is vaccinated,” he said.

Nonetheless, he plans to wear a mask at places where people are in close contact for hours, say a roof party in Brooklyn or a day at the beach this summer, if the group includes people who have yet to be vaccinated or if he doesn’t know everyone’s vaccine status.

Such behavior would be more stringent than this month’s updated guidance from the Centers for Disease Control and Prevention stating that vaccinated people no longer need to wear masks in nearly all settings. But Dr. Gonsalves said he would do so to show support for mask-wearing among unvaccinated people.

For travel, he recommended checking local vaccination rates and looking out for surges in infection rates to gauge the risk of encounters with unvaccinated people infected with the virus. “If you’re in a part of the country where you have 30 percent or 40 percent vaccination, instead of where you have 60 or 70 percent vaccination, you’re more likely to come in contact with somebody who is potentially positive and shedding virus,” he said. Traveling families that include unvaccinated kids or adults should continue to wear masks outdoors this summer, he added.

People who are vaccinated and have no underlying health conditions likely need not worry about visiting theme parks or attending a concert or baseball game in an undomed stadium, said Linsey Marr, an engineering professor at Virginia Tech with expertise in how viruses move in air. (Stadiums with domes or roofs can trap air, thus increasing the risk of viral spread.)

However, in hot spots with Covid-19 vaccination rates below 30 or 40 percent or where dashboards show more than an average of 10 daily infections per 100,000 people in a seven- or 14-day period, Dr. Marr said she would wear a mask in a crowded outdoor setting, despite being vaccinated.

And unvaccinated children and adults should mask up while standing in lines, where people tend to clot for long spells, Dr. Marr said. She would want her two children, one of whom is partially vaccinated, to wear masks at a theme park any time they came within six feet of others; she would don hers too, in solidarity.

With vaccines anticipated to be authorized for use in U.S. children under 12 no sooner than late this summer, decisions about outdoor activities with groups of children are more complex. Hold children’s parties in a park or big yard, if possible, and keep them small, Dr. Gonsalves said. A party of 30 kids with 50 or so parents, some of whom are unvaccinated, would make him wary. Dr. Marr said that bounce houses at outdoor children’s parties should be limited to half their capacity.

Blurred Lines

Last November, Nooshin Razani, an associate professor of epidemiology and biostatistics at the University of California, San Francisco, was an author on a systematic review of published outdoor virus-transmission studies that has become influential among policymakers. Her research turned up findings of respiratory diseases spreading at big gatherings that took place largely outdoors but also included indoor dining and indoor overnight stays.

“When we talk about indoors versus outdoors, it’s not very binary actually,” Dr. Razani said.

Absolute statements about outdoor coronavirus risks this summer trouble Michael Osterholm, an epidemiologist and the director of the Center for Infectious Disease Research and Policy at the University of Minnesota. Many people incorrectly assume that outdoor activities are entirely risk-free when it comes to the coronavirus, he said. And he opposed advising people to make outdoor plans based on local coronavirus infection, Covid-19 hospitalization or vaccination numbers, because individual and community circumstances vary too much.

“If you’re going to a family reunion, you can look at the rates of infection in your community,” he said. “But at a lot of big outdoor events, if you have a person coming from an outside area, you have no idea where they are coming from in terms of risk.” He thinks some coronavirus transmission that happens outdoors is unreported or never traced to its outdoor origin, unlike a cluster of cases traced to the 10-day motorcycle rally last August in Sturgis, S.D., or those thought to have spread last July at a concert in Minnesota.

People at an increased risk for Covid-19 — be that from being unvaccinated, an underlying condition or a suppressed or weakened immune system — should wear an N95 respirator mask if they are stationary in a big crowd outdoors for hours, he said. Those who are not young, healthy, vaccinated adults, should still avoid large, packed crowds, especially for extended periods of time, as well as any areas where air is trapped.

At this point in the pandemic, people have come to crave clear lines around coronavirus safety issues. “And unfortunately, this is not Oz,” Dr. Osterholm said, referring to the land where wizards and witches can be all-knowing. “There is not a simple answer.”

Robin Lloyd is a contributing editor at Scientific American magazine.

Why the C.D.C. Changed Its Advice on Masks

Two scientific findings altered the calculus: Vaccinated people don’t transmit the virus, and the shots are effective against variants.

Advice from federal health officials that fully vaccinated people could drop their masks in most settings came as a surprise to Americans, from state officials to scientific experts. Even the White House got less than a day’s notice from the Centers for Disease Control and Prevention, the press secretary, Jen Psaki, said at a news briefing on Friday.

“The C.D.C., the doctors and medical experts there, are the ones who determined what this guidance would be based on their own data, and what the timeline would be,” Ms. Psaki said. “That was not a decision directed by or made by the White House.”

For months, federal officials have vigorously warned that wearing masks and social distancing were necessary to contain the pandemic. So what changed?

Introducing the new recommendations on Thursday, Dr. Rochelle P. Walensky, the C.D.C. director, cited two recent scientific findings as significant factors: Few vaccinated people become infected with the virus, and transmission seems rarer still; and the vaccines appear to be effective against all known variants of the coronavirus.

There is no doubt at this point that the vaccines are powerful. On Friday, the C.D.C. released results from another large study showing that the vaccines made by Pfizer-BioNTech and Moderna are 94 percent effective in preventing symptomatic illness in those who were fully vaccinated, and 82 percent effective even in those only partly vaccinated.

“The science is quite clear on this,” said Zoë McLaren, a health policy expert at the University of Maryland, Baltimore County. Mounting evidence indicates that people who are vaccinated are highly unlikely to catch or transmit the virus, she noted.

The risk “is definitely not zero, but it’s clear that it’s very low,” she said.

One of the lingering concerns among scientists had been that even a vaccinated person might carry the virus — perhaps briefly, without symptoms — and spread it to others. But C.D.C. research, including the new study, has consistently found few infections among those who received the Pfizer-BioNTech and Moderna vaccines.

“This study, added to the many studies that preceded it, was pivotal to C.D.C. changing its recommendations for those who are fully vaccinated against Covid-19,” Dr. Walensky said in a statement on Friday.

Other recent studies confirm that people who are infected after vaccination carry too little virus to infect others, said Florian Krammer, a virologist at the Icahn School of Medicine at Mount Sinai.

“It’s really hard to even sequence the virus sometimes because there’s very little virus, and it’s there for a short period of time,” he said.

Still, most of the data has been gathered on the Pfizer-BioNTech and Moderna vaccines, Dr. Krammer cautioned. Because Johnson & Johnson’s vaccine was authorized later, there are fewer studies assessing its effectiveness.

In clinical trials, the Johnson & Johnson vaccine had 72 percent efficacy — lower than the figure for the Pfizer and Moderna vaccines. And effectiveness was measured in terms of moderate and severe disease, rather than mild disease.

“It’s a very good vaccine, and I’m sure it will save many, many, many lives,” Dr. Krammer said. “But we need more data on how well the J.&J. vaccine prevents infection, and how well it prevents transmission.”

Variants of the virus have been a particular worry for scientists. While Dr. Walensky cited evidence showing that the mRNA vaccines like those from Pfizer and Moderna are effective against the variants circulating in the United States, there is little data about variants and the Johnson & Johnson vaccine. And new variants are emerging constantly.

“I’m not at all saying that this is now a big problem,” Dr. Krammer said. But before lifting the masking requirements, “I might have waited a little bit longer to look at the numbers.”

In a statement on Friday, a C.D.C. spokesman said, “All of the authorized vaccines provide strong protection against serious illness, hospitalization, and death, and we are accumulating data that our authorized vaccines are effective against the variants that are circulating in this country.”

Fully immunized people are unlikely to get seriously ill, even if they are infected with the coronavirus. The risk of infection is greater for the people around them — unvaccinated children and adults, or vaccinated people who remain unprotected because of a medical condition or treatment.

C.D.C. officials said they weighed those factors and were confident in their assessment of the science. And the new advice has other salutary effects, rewarding fully immunized people by giving them permission to end their social isolation — and perhaps incentivizing others to opt for vaccination.

The new advice “signals that we really are on the final stretch here, and I think that’s a very good thing for people,” said Dr. Joshua Sharfstein, the vice dean for public health practice and community engagement at Johns Hopkins University Bloomberg School of Health.

“It’s unlikely that we’re going to have another huge surge in cases,” he added. “But will the final stretch last for weeks or months is still a question.”

The difficulty with the new recommendations, he and other experts said, is not so much the science underpinning them as their implementation.

Leaders at the state, city and county levels still have the authority to require masks even for vaccinated people, as the C.D.C. was quick to acknowledge on Thursday. After the agency’s announcement, some states instantly lifted mask mandates, while others said they would need more time to weigh the evidence.

But in states without mask mandates, the onus of checking vaccination status will fall on shopkeepers, restaurant workers, school officials and workplace managers.

“Without a means to verify vaccination, we will have to rely on an honor system,” said Caitlin Rivers, an epidemiologist at Johns Hopkins University.

The number of cases in the country is the lowest it has been since September, and many experts support lifting mask mandates in much of the country. But doing so will be riskier in places like Michigan, where there are more cases, and for people who are unprotected, including children under 12 and people with a weak immune systems, Dr. Rivers said.

“People who are unvaccinated should continue to wear masks in public indoors and avoid crowds,” she said.

In Nacogdoches, Texas, Dr. Ahammed Hashim fretted that only 36 percent of the population was immunized and the pace seemed to have stalled. And yet only one or two people in 10 in the local shops wore masks.

“I think the C.D.C. might send a wrong message saying that everything’s OK,” said Dr. Hashim, a pulmonologist. “It would feel much better if we had a 60 or 70 percent vaccination.”

The C.D.C.’s guidance is intended for fully vaccinated individuals, and should only be interpreted as such, Dr. Sharfstein cautioned. Nationwide, only 36 percent of the population is fully vaccinated.

“What we’re just seeing is a little bit of the distance between advice that is entirely appropriate for people who are vaccinated, and the reality that there are places that still are seeing viral transmission and a lot of people who aren’t vaccinated,” he said.

Individuals may make choices based on their perception of their own risks, but state and local leaders must decide what’s best for the community based on the rate of infections. “Those are two different things,” Dr. Sharfstein said. “And when they get conflated, that’s when people may make bad judgments about policy.”

The new guidelines should serve as a reminder to health officials to step up their outreach and investment to ensure that everyone has access to vaccines, Dr. McLaren said. Parents of children under 12 should continue to urge them to wear masks indoors.

The C.D.C.’s new policy shifts the onus onto the immunocompromised as well, to protect themselves from unmasked and unvaccinated people.

“When we make policy, we need to balance the needs and desires of everyone,” Dr. McLaren said. “We could keep masking forever, but there are benefits to getting back to a life that looks more normal.”

Health officials should emphasize that the situation may yet change, and official recommendations with it, she added: “We really need to practice being good at responding to changing situations.”

Covid Pandemic Demands Air Quality Changes in the Workplace, Researchers Say

The researchers issued a call to action to improve indoor air quality as a safeguard against the spread of contagions like the coronavirus.

Clean water in 1842, food safety in 1906, a ban on lead-based paint in 1971. These sweeping public health reforms transformed not just our environment but expectations for what governments can do.

Now it’s time to do the same for indoor air quality, according to a group of 39 scientists. In a manifesto of sorts published on Thursday in the journal Science, the researchers called for a “paradigm shift” in how citizens and government officials think about the quality of the air we breathe indoors.

The timing of the scientists’ call to action coincides with the nation’s large-scale reopening as coronavirus cases steeply decline: Americans are anxiously facing a return to offices, schools, restaurants and theaters — exactly the type of crowded indoor spaces in which the coronavirus is thought to thrive.

There is little doubt now that the coronavirus can linger in the air indoors, floating far beyond the recommended six feet of distance, the experts declared. The accumulating research puts the onus on policymakers and building engineers to provide clean air in public buildings and to minimize the risk of respiratory infections, they said.

“We expect to have clean water from the taps., said Lidia Morawska, the group’s leader and an aerosol physicist at Queensland University of Technology in Australia. “We expect to have clean, safe food when we buy it in the supermarket. In the same way, we should expect clean air in our buildings and any shared spaces.”

Meeting the group’s recommendations would require new workplace standards for air quality, but the scientists maintained that the remedies do not have to be onerous. Air quality in buildings can be improved with a few simple fixes, they said: adding filters to existing ventilation systems, using portable air cleaners and ultraviolet lights — or even just opening the windows where possible.

Dr. Morawska led a group of 239 scientists who last year called on the World Health Organization to acknowledge that the coronavirus can spread in tiny droplets, or aerosols, that drift through the air. The W.H.O. had insisted that the virus spreads only in larger, heavier droplets and by touching contaminated surfaces, contradicting its own 2014 rule to assume all new viruses are airborne.

The W.H.O. conceded on July 9 that transmission of the virus by aerosols could be responsible for “outbreaks of Covid-19 reported in some closed settings, such as restaurants, nightclubs, places of worship or places of work where people may be shouting, talking or singing,” but only at short range.

“For the source room, clearly more ventilation is a good thing,” said one of the study’s authors. But that air goes somewhere. Maybe more ventilation is not always the solution.”
“For the source room, clearly more ventilation is a good thing,” said one of the study’s authors. But that air goes somewhere. Maybe more ventilation is not always the solution.”L. Morawska et al., Science 2021, with permission of AAAS

The pressure to act on preventing airborne spread has recently been escalating. In February, more than a dozen experts petitioned the Biden administration to update workplace standards for high-risk settings like meatpacking plants and prisons, where Covid outbreaks have been rampant.

Last month, a separate group of scientists detailed 10 lines of evidence that support the importance of airborne transmission indoors.

On April 30, the W.H.O. inched forward and allowed that in poorly ventilated spaces, aerosols “may remain suspended in the air or travel farther than 1 meter (long-range).” The Centers for Disease Control and Prevention, which had also been slow to update its guidelines, recognized last week that the virus can be inhaled indoors, even when a person is more than six feet away from an infected individual.

“They have ended up in a much better, more scientifically defensible place,” said Linsey Marr, an expert in airborne viruses at Virginia Tech, and a signatory to the letter.

“It would be helpful if they were to undertake a public service messaging campaign to publicize this change more broadly,” especially in parts of the world where the virus is surging, she said. For example, in some East Asian countries, stacked toilet systems could transport the virus between floors of a multistory building, she noted.

More research is also needed on how the virus moves indoors. Researchers at the Department of Energy’s Pacific Northwest National Laboratory modeled the flow of aerosol-sized particles after a person has had a five-minute coughing bout in one room of a three-room office with a central ventilation system. Clean outdoor air and air filters both cut down the flow of particles in that room, the scientists reported in April.

But rapid air exchanges — more than 12 in an hour — can propel particles into connected rooms, much as secondhand smoke can waft into lower levels or nearby rooms.

“For the source room, clearly more ventilation is a good thing,” said Leonard Pease, a chemical engineer and lead author of the study. “But that air goes somewhere. Maybe more ventilation is not always the solution.”

In the United States, the C.D.C.’s concession may prompt the Occupational Safety and Health Association to change its regulations on air quality. Air is harder to contain and clean than food or water. But OSHA already mandates air-quality standards for certain chemicals. Its guidance for Covid does not require improvements to ventilation, except for health care settings.

“Ventilation is really built into the approach that OSHA takes to all airborne hazards,” said Peg Seminario, who served as director of occupational safety and health for the A.F.L.-C.I.O. from 1990 until her retirement in 2019. “With Covid being recognized as an airborne hazard, those approaches should apply.”

In January, President Biden directed OSHA to issue emergency temporary guidelines for Covid by March 15. But OSHA missed the deadline: Its draft is reportedly being reviewed by the White House’s regulatory office.

Workers installed ventilation equipment at University Hospital in Augusta, Ga., last year. As a group of scientists called for new workplace air quality improvements, they contended the measures would not be onerous. Michael Holahan/The Augusta Chronicle, via Associated Press

In the meantime, businesses can do as much or as little as they wish to protect their workers. Citing concerns of continued shortages of protective gear, the American Hospital Association, an industry trade group, endorsed N95 respirators for health care workers only during medical procedures known to produce aerosols, or if they have close contact with an infected patient. Those are the same guidelines the W.H.O. and the C.D.C. offered early in the pandemic. Face masks and plexiglass barriers would protect the rest, the association said in March in a statement to the House Committee on Education and Labor.

“They’re still stuck in the old paradigm, they have not accepted the fact that talking and coughing often generate more aerosols than do these so-called aerosol-generating procedures,” Dr. Marr said of the hospital group.

“We know that Plexiglas barriers do not work,” she said, and may in fact increase the risk, perhaps because they inhibit proper airflow in a room.

The improvements do not have to be expensive: In-room air filters are reasonably priced at less than 50 cents per square foot, although a shortage of supply has raised prices, said William Bahnfleth, professor of architectural engineering at Penn State University, and head of the Epidemic Task Force at Ashrae (the American Society of Heating, Refrigerating and Air-Conditioning Engineers), which sets standards for such devices. UV lights that are incorporated into a building’s ventilation system can cost up to roughly $1 per square foot; those installed room by room perform better but could be 10 times as expensive, he said.

If OSHA rules do change, demand could inspire innovation and slash prices. There is precedent to believe that may happen, according to David Michaels, a professor at George Washington University who served as OSHA director under President Barack Obama.

When OSHA moved to control exposure to a carcinogen called vinyl chloride, the building block of vinyl, the plastics industry warned it would threaten 2.1 million jobs. In fact, within months, companies “actually saved money and not a single job was lost,” Dr. Michaels recalled.

In any case, absent employees and health care costs can prove to be more costly than updates to ventilation systems, the experts said. Better ventilation will help thwart not just the coronavirus, but other respiratory viruses that cause influenza and common colds, as well as pollutants.

Before people realized the importance of clean water, cholera and other waterborne pathogens claimed millions of lives worldwide every year.

“We live with colds and flus and just accept them as a way of life,” Dr. Marr said. “Maybe we don’t really have to.”

To Vaccinate Younger Teens, States and Cities Look to Schools, Camps, Even Beaches

The F.D.A.’s authorization of Pfizer’s Covid shot for 12- to 15-year-olds is a milestone in battling the coronavirus, but actually getting them vaccinated involves new challenges.

Abby Goodnough and

Hundreds of high school seniors rode in bus caravans recently to a mass vaccination site outside Hartford, Conn., where they got Covid-19 shots as a D.J. played Lady Gaga and a selfie backdrop awaited.

Now, the race is on to get to their younger siblings — and all the nation’s nearly 17 million 12- to 15-year-olds, after the Food and Drug Administration authorized the Pfizer-BioNTech vaccine for their age group.

The F.D.A.’s decision, announced Monday afternoon, presents a bright new opportunity in the push for broad immunity against the coronavirus in the United States, but the challenges are more daunting than for immunizing older, more independent teenagers.

A recent survey by the Kaiser Family Foundation’s Vaccine Monitor found that many parents — even those who eagerly got their own Covid shots — are reluctant to vaccinate pubescent children. Yet doing so will be critical for further reducing transmission of the virus, smoothly reopening middle and high schools and regaining some sense of national normalcy.

“The game changes when you go down as young as 12 years old,” said Nathan Quesnel, the superintendent of schools in East Hartford, adding, “You need to have a different level of sensitivity.”

States, counties and school districts around the country are trying to figure out the most reassuring and expedient ways to reach younger adolescents as well as their parents, whose consent is usually required by state law. They are making plans to offer vaccines not only in schools, but also at pediatricians’ offices, day camps, parks and even beaches.

Children’s Minnesota, a Minneapolis-based hospital system where the main Covid vaccination site has offered stress balls, colored lights and images of playful dolphins projected on the ceiling, is planning to provide shots beginning later this week in at least a dozen middle schools and a Y.W.C.A.

In Columbus, Ohio, public health nurses will drive a mobile vaccination unit around neighborhoods “just like you would an ice cream truck,” said Dr. Mysheika Roberts, the city health commissioner. In Connecticut, Community Health Center, a statewide primary care provider that vaccinated the busloads of high school seniors, is aiming to reach younger adolescents by offering shots at amusement parks, beaches and camps, among other locales.

“You’re going to Dollar General?” said Yvette Highsmith-Francis, a vice president of Community Health Center. “Guess what? We’re in the parking lot.”

But with the school year ending soon, many health officials are racing against the academic clock to schedule both recommended doses, seeing schools as the best place to reach many students at once.

A vial of the Pfizer vaccine at the Denver School of Science and Technology Green Valley Ranch this month.
A vial of the Pfizer vaccine at the Denver School of Science and Technology Green Valley Ranch this month.Kevin Mohatt for The New York Times

“We have a very finite amount of time,” said Dr. Anne Zink, the chief medical officer for Alaska. “In Alaska, kids go to the wind as soon as summer hits, so our opportunity to get them is now.”

A number of places are revving up vaccination efforts in schools. In Colorado, Denver Health will expand clinics it operates in six public schools to middle school students. For the last few weeks, it has provided 150 to 400 vaccines every Saturday and Sunday, reaching not just high school juniors and seniors but sometimes their parents and older siblings, too.

“It’s been really successful because we are doing it in their communities, where the kids are familiar,” said Dr. Sonja O’Leary, the medical director for Denver Health’s school-based health centers.

Other states believe pediatricians’ and family doctors’ offices will be the best places to catch teenagers — and children as young as infants as companies plan eventually to seek authorization for the shots to be given to the youngest children. Until recently, few doctors had vaccines on hand for patients. But in recent weeks, the Centers for Disease Control and Prevention has made a major push to enroll pediatricians to give the shots.

The thinking is that pediatricians are in the best position to field questions from parents and children. Not only are they experienced in giving routine childhood vaccinations, but they are also often a household’s most trusted source of health information.

President Biden announced plans last week to ship doses of the Pfizer vaccine directly to pediatricians’ offices, and he said that about 20,000 pharmacy sites were also ready to administer the vaccine to younger adolescents.

There are also practical issues. Staggering Covid shots around the routine vaccines required for school in September — which many children are behind on because of the pandemic — will be complicated. According to the C.D.C., no vaccines can be given two weeks before and after a Covid vaccine.

Pediatricians are used to talking to nervous parents about vaccines, but they concede that the Covid shot poses unique persuasion challenges. To help these conversations, the American Academy of Pediatrics has posted answers to frequently asked questions and has been holding virtual training workshops.

Pediatricians say they have been getting vaccine questions for months.

From left, Garrett Bates, his sons Christopher Bates and Preston Janac; Precious Wright, his partner; and his daughter Tyshawnie Bates, of Hollywood, Fla.Octavio Jones for The New York Times

Many parents and teenagers have been stirred by false information coursing across the internet about the shots’ impact on fertility and menstrual cycles, said Dr. Hina Talib, an adolescent medicine specialist at Children’s Hospital at Montefiore Medical Center in the Bronx, who posts on Instagram as @teenhealthdoc.

“With hormones floating around during puberty, parents ask if it’s dangerous for their child to be given a vaccine during that time,” Dr. Talib said. The questions reflect the parents’ thoughtfulness, she said, and need to be addressed respectfully.

Dr. Talib, whose patients are often Black or Latino and recent immigrants, said that many hear vaccine resistance at home. “We have to validate parental anxiety and mistrust of medicine and be very open to listening to what their experiences have been,” she said.

Garrett Bates and Precious Wright, who live in Hollywood, Fla., have tentatively decided to get themselves vaccinated, but they are holding off on their four children, ages 12 through 19, just now.

It has been a tough year: Two of the children attended school in person, two were remote. Yet, even though vaccination offers the possibility that all their children will have a more engaged, carefree life, Ms. Wright wants to see how others their age fare first.

“From what I know, you take the vaccine and some people feel sick and it lasts a couple of hours or a day,” she said. “My immune system is stronger than the kids’. I don’t know if they could shake off those effects as quickly as mine.”

For some teenagers, anxious about bringing the virus home to vulnerable relatives, the vaccine represents liberation — from those worries as well as constraints on seeing friends.

“The kids have ‘shot envy,’” Dr. Talib said.

Dr. Nicole Baldwin, a pediatrician in Cincinnati whose health-related TikTok videos now feature one for the Pfizer vaccine, said she was surprised by how excited many of her teenaged patients were about the vaccine. “I’ll ask, ‘Have your friends gotten it?’ And they’re saying, ‘Yes!’”

But she also has patients, including those with high-risk medical conditions that make them vulnerable to Covid, who are not getting it. “Their parents say no,” she said.

When parent and child are at odds about the vaccine, the pediatrician has a tricky path to walk. And when divorced parents disagree over whether their child should get the vaccine, those discussions become even more difficult.

Not all teenagers long for the vaccine. Many hate getting shots. Others say that because young people often get milder cases of Covid, why risk a new vaccine?

Patsy Stinchfield, a nurse practitioner who oversees vaccination for Children’s Minnesota, has stark evidence that some cases in young people can be serious. Not only have more children with Covid been admitted to the hospital recently, but its intensive care unit also has Covid patients who are 13, 15, 16 and 17 years old.

The F.D.A.’s new authorization means all those patients would be eligible for the shots, she noted. “If you can prevent your child ending up in the I.C.U. with a safe vaccine, why wouldn’t you ?” she said.

Mr. Quesnel, the East Hartford, Conn., superintendent, said the most powerful message for reaching older adolescents would probably appeal just as much to younger ones. Rather than focusing on the fact that the shot will protect them, he said, they seize on the idea that it will keep them from having to quarantine if they are exposed.

“They’re not so afraid of the health care dangers from Covid but the social losses that come along with it,” he said, adding that 60 percent of his district’s seniors, or about 300 students, got their first dose at a mass vaccination site run by Community Health Center on April 26. “Some of our greatest leverage right now is that social component — ‘You won’t be quarantined.’”

Michael Jackson of North Port, Fla., can’t wait for his 14-year-old son, Devin, to get the vaccine. During the past year, he said, his son’s beloved Little League games went on hiatus and the family had to suspend their regular Sunday suppers with grandparents And Devin, an eighth grader, had to quarantine three times after being exposed to Covid.

Other parents have challenged Mr. Jackson about his plans to get Devin vaccinated. “They say to me, ‘How can you put that in your body?’” he said, adding, “And meanwhile they’re eating a Big Mac and drinking a can of soda?”

Michael Jackson, left, of North Port, Fla., is eager for his 14-year-old son, Devin, to get vaccinated.Octavio Jones for The New York Times

Before any younger adolescents can receive the shots, the C.D.C.’s vaccine advisory committee will meet in the coming days to review the clinical trial data and make recommendations for the vaccine’s use in the 12-to-15 age group.

Within months, eligibility for the vaccines is expected to expand to even younger children. Pfizer expects to seek emergency authorization in September to administer its vaccine to children between the ages of 2 and 11. Moderna’s clinical trial results for its vaccine in 12- to 17-year-olds are expected in the next few weeks, and those from a trial of its vaccine in children 6 months to 12 years old in the second half of this year.

All 50 states require certain vaccines for children who attend school, but those mandates apply only to vaccines that have been fully approved by the F.D.A., a status the Covid shots have not yet achieved. And even when the F.D.A. approves the vaccines, any state-legislated mandates would most likely allow students to opt out for medical, religious and sometimes even philosophical reasons, as they do for other childhood shots.

In Columbus, Dr. Roberts already has a good sense of the challenge ahead. Her department worked with the local children’s hospital to offer vaccinations to older teenagers at high schools over the last month, hoping to reach up to 6,000 of them.

“We only got about 600,” she said, noting that parental fears about infertility were the most common reason for refusing the shots. Now she and her staff are considering offering incentives like free meals and grocery store gift cards to parents, and perhaps prizes for children as well.

“We’re committed to getting this population vaccinated,” she said, “so we’re going to look at anything and everything.”

Drug Overdose Deaths Have Surged During the Pandemic, C.D.C. Says

The latest numbers surpass even the yearly tolls during the height of the opioid epidemic and mark a reversal of progress against addiction in recent years.

WASHINGTON — More than 87,000 Americans died of drug overdoses over the 12-month period that ended in September, according to preliminary federal data, eclipsing the toll from any year since the opioid epidemic began in the 1990s.

The surge represents an increasingly urgent public health crisis, one that has drawn less attention and fewer resources while the nation has battled the coronavirus pandemic.

Deaths from overdoses started rising again in the months leading up to the coronavirus pandemic — after dropping slightly in 2018 for the first time in decades — and it is hard to gauge just how closely the two phenomena are linked. But the pandemic unquestionably exacerbated the trend, which grew much worse last spring: The biggest jump in overdose deaths took place in April and May, when fear and stress were rampant, job losses were multiplying and the strictest lockdown measures were in effect.

Many treatment programs closed during that time, at least temporarily, and “drop-in centers” that provide support, clean syringes and naloxone, the lifesaving medication that reverses overdoses, cut back services that in many cases have yet to be fully restored.

The preliminary data released Wednesday by the Centers for Disease Control and Prevention show a 29 percent rise in overdose deaths from October 2019 through September 2020 — the most recent data available — compared with the previous 12-month period. Illicitly manufactured fentanyl and other synthetic opioids were the primary drivers, although many fatal overdoses have also involved stimulant drugs, particularly methamphetamine.

And unlike in the early years of the opioid epidemic, when deaths were largely among white Americans in rural and suburban areas, the current crisis is affecting Black Americans disproportionately.

“The highest increase in mortality from opioids, predominantly driven by fentanyl, is now among Black Americans,” Dr. Nora Volkow, the director of the National Institute on Drug Abuse, said at a national addiction conference last week. “And when you look at mortality from methamphetamine, it’s chilling to realize that the risk of dying from methamphetamine overdose is 12-fold higher among American Indians and Alaskan Natives than other groups.”

Dr. Volkow added that more deaths than ever involved drug combinations, typically of fentanyl or heroin with stimulants.

“Dealers are lacing these non-opioid drugs with cheaper, yet potent, opioids to make a larger profit,” she said. “Someone who’s addicted to a stimulant drug like cocaine or methamphetamine is not tolerant to opioids, which means they are going to be at high risk of overdose if they get a stimulant drug that’s laced with an opioid like fentanyl.”

The surging death rate eclipses modest gains made during President Trump’s term against the nation’s entrenched addiction epidemic. During his administration, several billion dollars in grants to states allowed more drug users to get access to the three F.D.A.-approved medications for opioid addiction — methadone, buprenorphine and naltrexone — that work by suppressing cravings and symptoms of withdrawal. Naloxone, the overdose-reversing drug that has saved thousands of lives, also became widely distributed.

Brendan Saloner, an associate professor at the Johns Hopkins School of Public Health who studies access to addiction treatment, said surveys that he and a colleague, Susan Sherman, conducted of drug users and people in treatment in 11 states during the pandemic found that many had used drugs more often during that time — and used them alone more often, likely because of lockdowns and social distancing. Well over half the participants also said the drugs they used had been cut or mixed more than usual, another red flag.

“The data points corroborate something I believe, which is that people who were already using drugs started using in ways that were higher risk — especially using alone and from a less reliable supply,” Dr. Saloner said.

A vigil remembering people who died of drug overdoses in Gloucester, Mass., in August.
A vigil remembering people who died of drug overdoses in Gloucester, Mass., in August.CJ Gunther/EPA, via Shutterstock

Although President Biden has yet to appoint a permanent “drug czar,” his Office of National Drug Control Policy released an outline last week of its priorities for addressing the addiction and overdose epidemic. They include measures the Trump administration also embraced, like expanding access to medication treatment for opioid addiction, but diverged from the Trump agenda by pledging to address “systemic inequities” in prevention, treatment and recovery.

And although the Biden plan embraced medications for addiction, shortly after his inauguration, Mr. Biden reversed a move by the Trump administration that would have made it easier for doctors to prescribe buprenorphine, a lifesaving anti-craving medication, for opioid addiction.

Members of the new administration said at the time that the plan was not legally sound, but one of the priorities listed in the new document is to “remove unnecessary barriers to prescribing buprenorphine.”

On Tuesday, several dozen organizations that work on addiction and other health issues asked Mr. Biden’s health and human services secretary, Xavier Becerra, to “act with urgency” and eliminate the rule that doctors go through a day of training before getting federal permission to prescribe buprenorphine. Many addiction experts are also calling for abolishing rules that had already been relaxed during the pandemic so that patients don’t have to come to clinics or doctors’ offices for addiction medications.

Although many programs offering treatment, naloxone and other services for drug users have reopened at least partly as the pandemic has dragged on, many others remain closed or severely curtailed, particularly if they operated on a shoestring budget to begin with.

Sara Glick, an assistant professor of medicine at the University of Washington, said a survey of about 30 syringe exchange programs that she conducted last spring found that many closed temporarily early in the pandemic. After reopening, she said, many programs cut back services or the number of people they could help.

“With health departments spending so much on Covid, some programs have really had to cut their budgets,” she said. “That can mean seeing fewer participants, or pausing their H.I.V. and hepatitis C testing.”

At the same time, increases in H.I.V. cases have been reported in several areas of the country with heavy injection drug use, including two cities in West Virginia, Charleston and Huntington, and Boston. West Virginia’s legislature passed a law last week placing new restrictions on syringe exchange programs, which advocates of the programs said would force many to close.

Mr. Biden’s American Rescue Plan Act includes $1.5 billion for the prevention and treatment of substance use disorders, as well as $30 million in funding for local services that benefit people with addiction, including syringe exchange programs. The latter is significant because while federal funds still largely cannot be spent on syringes for people who use drugs, the restriction does not apply to money from the stimulus package, according to the Office of Drug Control Policy. Last week, the administration announced that federal funding could now be used to buy rapid fentanyl test strips, which can be used to check whether drugs have been mixed or cut with fentanyl.

Fentanyl or its analogues have increasingly been detected in counterfeit pills being sold illegally as prescription opioids or benzodiazepines — sedatives like Xanax that are used as anti-anxiety medications — and particularly in meth.

Northeastern states that had been hit hardest by opioid deaths in recent years saw some of the smallest increases in deaths in the first half of the pandemic year, with the exception of Maine. The hardest-hit states included West Virginia and Kentucky, which have long ranked at the top in overdose deaths, but also western states like California and Arizona and southern ones like Louisiana, South Carolina and Tennessee.

Has the Era of Overzealous Cleaning Finally Come to an End?

This week, the C.D.C. acknowledged what scientists have been saying for months: The risk of catching the coronavirus from surfaces is low.

When the coronavirus began to spread in the United States last spring, many experts warned of the danger posed by surfaces. Researchers reported that the virus could survive for days on plastic or stainless steel, and the Centers for Disease Control and Prevention advised that if someone touched one of these contaminated surfaces — and then touched their eyes, nose or mouth — they could become infected.

Americans responded in kind, wiping down groceries, quarantining mail and clearing drugstore shelves of Clorox wipes. Facebook closed two of its offices for a “deep cleaning.” New York’s Metropolitan Transportation Authority began disinfecting subway cars every night.

But the era of “hygiene theater” may have come to an unofficial end this week, when the C.D.C. updated its surface cleaning guidelines and noted that the risk of contracting the virus from touching a contaminated surface was less than 1 in 10,000.

“People can be affected with the virus that causes Covid-19 through contact with contaminated surfaces and objects,” Dr. Rochelle Walensky, the director of the C.D.C., said at a White House briefing on Monday. “However, evidence has demonstrated that the risk by this route of infection of transmission is actually low.”

The admission is long overdue, scientists say.

“Finally,” said Linsey Marr, an expert on airborne viruses at Virginia Tech. “We’ve known this for a long time and yet people are still focusing so much on surface cleaning.” She added, “There’s really no evidence that anyone has ever gotten Covid-19 by touching a contaminated surface.”

During the early days of the pandemic, many experts believed that the virus spread primarily through large respiratory droplets. These droplets are too heavy to travel long distances through the air but can fall onto objects and surfaces.

In this context, a focus on scrubbing down every surface seemed to make sense. “Surface cleaning is more familiar,” Dr. Marr said. “We know how to do it. You can see people doing it, you see the clean surface. And so I think it makes people feel safer.”

A “sanitization specialist” at an Applebee’s Grill and Bar in Westbury, N.Y., wiping down a used pen last year. Restaurants and other businesses have highlighted extra cleaning in their marketing since the pandemic began.
A “sanitization specialist” at an Applebee’s Grill and Bar in Westbury, N.Y., wiping down a used pen last year. Restaurants and other businesses have highlighted extra cleaning in their marketing since the pandemic began.Hiroko Masuike/The New York Times

But over the last year, it has become increasingly clear that the virus spreads primarily through the air — in both large and small droplets, which can remain aloft longer — and that scouring door handles and subway seats does little to keep people safe.

“The scientific basis for all this concern about surfaces is very slim — slim to none,” said Emanuel Goldman, a microbiologist at Rutgers University, who wrote last summer that the risk of surface transmission had been overblown. “This is a virus you get by breathing. It’s not a virus you get by touching.”

The C.D.C. has previously acknowledged that surfaces are not the primary way that the virus spreads. But the agency’s statements this week went farther.

“The most important part of this update is that they’re clearly communicating to the public the correct, low risk from surfaces, which is not a message that has been clearly communicated for the past year,” said Joseph Allen, a building safety expert at the Harvard T.H. Chan School of Public Health.

Catching the virus from surfaces remains theoretically possible, he noted. But it requires many things to go wrong: a lot of fresh, infectious viral particles to be deposited on a surface, and then for a relatively large quantity of them to be quickly transferred to someone’s hand and then to their face. “Presence on a surface does not equal risk,” Dr. Allen said.

In most cases, cleaning with simple soap and water — in addition to hand-washing and mask-wearing — is enough to keep the odds of surface transmission low, the C.D.C.’s updated cleaning guidelines say. In most everyday scenarios and environments, people do not need to use chemical disinfectants, the agency notes.

“What this does very usefully, I think, is tell us what we don’t need to do,” said Donald Milton, an aerosol scientist at the University of Maryland. “Doing a lot of spraying and misting of chemicals isn’t helpful.”

Still, the guidelines do suggest that if someone who has Covid-19 has been in a particular space within the last day, the area should be both cleaned and disinfected.

“Disinfection is only recommended in indoor settings — schools and homes — where there has been a suspected or confirmed case of Covid-19 within the last 24 hours,” Dr. Walensky said during the White House briefing. “Also, in most cases, fogging, fumigation and wide-area or electrostatic spraying is not recommended as a primary method of disinfection and has several safety risks to consider.”

And the new cleaning guidelines do not apply to health care facilities, which may require more intensive cleaning and disinfection.

Saskia Popescu, an infectious disease epidemiologist at George Mason University, said that she was happy to see the new guidance, which “reflects our evolving data on transmission throughout the pandemic.”

But she noted that it remained important to continue doing some regular cleaning — and maintaining good hand-washing practices — to reduce the risk of contracting not just the coronavirus but any other pathogens that might be lingering on a particular surface.

Dr. Allen said that the school and business officials he has spoken with this week expressed relief over the updated guidelines, which will allow them to pull back on some of their intensive cleaning regimens. “This frees up a lot of organizations to spend that money better,” he said.

Schools, businesses and other institutions that want to keep people safe should shift their attention from surfaces to air quality, he said, and invest in improved ventilation and filtration.

“This should be the end of deep cleaning,” Dr. Allen said, noting that the misplaced focus on surfaces has had real costs. “It has led to closed playgrounds, it has led to taking nets off basketball courts, it has led to quarantining books in the library. It has led to entire missed school days for deep cleaning. It has led to not being able to share a pencil. So that’s all that hygiene theater, and it’s a direct result of not properly classifying surface transmission as low risk.”

Roni Caryn Rabin contributed reporting

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.”