Joe Palca

Are vaccinated people who get COVID as likely to spread the infection as unvaccinated people? Scientists don't think so.

Can a vaccinated person with a breakthrough infection infect others? Conventional wisdom says yes, but new research says it's not all that likely.

Pharmaceutical giant Merck announced promising results from a study of a new antiviral drug. Molnupiravir reduced COVID hospitalizations or death by 50% in a trial involving 775 volunteers.

A Food and Drug Administration panel voted against giving most Americans a third Pfizer vaccine despite President Biden's plan to provide a COVID-19 booster to anyone over the age of 16.

An independent committee of experts has recommended that the Food and Drug Administration should not allow Pfizer to provide a third dose of its COVID-19 vaccine to Americans older than 16.

The committee of independent experts advising the FDA on vaccines meets Friday. They'll be considering Pfizer's application to start offering COVID-19 vaccine boosters to all Americans older than 16.

Pfizer is seeking the FDA's permission to offer a third COVID-19 vaccine dose to those 16 and older. There's data that the vaccine's efficacy is waning and evidence that a booster can reverse that.

After vaccination, antibody levels can help predict how much protection a COVID-19 shot offers, scientists are learning. The finding could speed up the development of future vaccines.

The lab has access to a high-security facility that Pfizer needed to prove its COVID-19 vaccine was working. Now the scientists there are testing the vaccine's effectiveness against viral variants.

A COVID-19 vaccine for children younger than 12 is not yet available, but research is well underway and the first shot for some kids in this age group is expected in the fall, doctors say.

The Biden administration is close to advising fully vaccinated Americans to get COVID-19 booster shots after eight months, according to a source familiar with the discussions.

The FDA has authorized the use of a third dose of a COVID-19 vaccine for people with compromised immune systems. Why is the agency taking that step?

A study of a thousand women is underway to determine when during pregnancy is the best time to get a COVID-19 vaccine, and whether infants will be protected by the vaccine once they are born.

Scientists have been looking for some kind of marker in the blood that could be used to predict whether a COVID-19 vaccine is working or not — now, they think they have one.

To reach the innermost planet in our solar system, this European space probe needs a little help from the gravity of Venus.

Right now, only kids 12 and older can get a COVID-19 vaccine in the U.S. Studies underway at multiple sites are gathering data to see if the vaccine can be given to children as young as six months.

Breakthrough COVID-19 infections are still quite rare, but scientists are now learning more about the risks posed by the delta variant to people who are vaccinated.

Health officials around the world are adjusting their plans for combatting the coronavirus in light of the more infectious Delta variant — and evidence that even vaccinated people can spread it.

Pfizer presented data to investors showing that a third dose of its COVID-19 vaccine boosts immunity. The company believes everyone will need a boost eight to 12 months after receiving a second shot.

The FDA ordered Johnson and Johnson to put a label on its COVID-19 vaccine warning of the risk of a neurological disorder. Israel is offering booster shots to individuals who are immune compromised.