Joe Palca

Over 100 million Americans have received at least one dose of a COVID-19 vaccine. That number is climbing by about 3 million daily. We hear the latest information on how well the vaccines are working.

A viral TikTok makes vaccine science understandable and pretty funny (it's a horror film parody). NPR caught up with creator and star Vick Krishna — tech expert by day, videographer by night.

A study of nearly 2,300 volunteers shows Pfizer's COVID-19 vaccine appears to work in adolescents. There were 18 cases of COVID-19 in people who got a placebo and none in those who got the vaccine.

The COVID-19 vaccine made by Pfizer and BioNtech appears to work in children as young as 12. A small study was conducted in volunteers 12 to 15 years of age.

AstraZeneca was chastised by a committee charged with reviewing its COVID-19 vaccine study results. AstraZeneca claimed a vaccine efficacy of 79%, but the committee said that was using outdated data.

A U.S. trial of AstraZeneca's COVID-19 vaccine may have used outdated information. A statement by the National Institutes of Health says an incomplete view of efficacy data may have been provided.

Preliminary results from a study of AstraZeneca's COVID-19 vaccine indicates it's safe and effective. The company plans to file a request with the FDA for emergency authorization to distribute doses.

AstraZeneca says a study of its vaccine showed an efficacy of 79% for preventing symptomatic disease. The study may meet FDA requirements for considering the vaccine for emergency-use authorization.

Denmark has temporarily suspended giving people the AstraZeneca COVID-19 vaccine in order to investigate whether some potentially serious medical conditions are related to the vaccine.

Exposing people to a potentially fatal disease could hasten understanding of COVID-19 and development of new vaccines and treatments. But the risks of such studies raise serious ethical questions.

The Food and Drug Administration authorized Johnson & Johnson's vaccine for emergency use Saturday, a day after a panel of advisers to the agency voted unanimously in its favor.

The committee voted 22 to nothing in favor of the new vaccine.

An advisory committee to the Food and Drug Administration met to consider the application for emergency use authorization for the Janssen, the vaccine division of Johnson & Johnson, COVID-19 vaccine.

The Food and Drug Administration's vaccine advisory committee meets today to consider the emergency use authorization application from Johnson and Johnson for its COVID-19 vaccine.

Variants of the coronavirus have scientists in a scramble to assess the threat and prevent more surges. Meanwhile, vaccine manufacturers are looking at developing booster shots to address variants.

Another COVID-19 vaccine may soon be available. The Food and Drug Administration has conducted an evaluation of the application from Johnson & Johnson for emergency use authorization for its vaccine.

The Food and Drug Administration has released its assessment of an application from Johnson & Johnson for emergency use authorization for its vaccine. It finds the vaccine safe and effective.

NASA released videos of the rover called Perseverance as it descended to the surface of Mars. The space agency also outlined what the rover will be doing in its first few days on Mars.

NASA's six-wheeled rover landed successfully on Mars yesterday. NPR's Joe Palca talks about the descent and landing, and what's next for the mission.

NASA's six-wheeled rover landed on Mars today. It touched down in a crater that housed a lake 3.5 billion years ago, in search of signs of ancient microbial life.