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.
Deaths among people who have been fully vaccinated remain rare, but older adults and those with compromised immune systems are at much higher risk.
Rising immunity and modest changes in behavior may explain why cases are declining, but much remains unknown, scientists say.
So-called natural immunity varies from patient to patient, scientists say. Immunization is still the best choice after recovering from the disease.
Myocarditis, a rare side effect, occurs mostly after the second dose. So in some countries, officials are trying out single doses for children.
If you test positive in an at-home Covid test, you’re very likely carrying the virus.
Vaccinated kids aged 5 to 11 showed evidence of protection against the virus, the company said. The data must be reviewed by the F.D.A. before children can be inoculated.
Here’s what to keep in mind.
If you’re vaccinated, you should think about a number of variables, including your overall health, where you live and the risks you take.
Vaccination remains the best defense, health experts say. But some infections occur regardless, and can come as a traumatic surprise.