NOEL KING, HOST:
A decision about booster shots for COVID could be coming today. An advisory committee to the FDA meets to consider Pfizer's application to offer a third dose of its vaccine to all Americans who are older than 16. Now, President Biden has said he wants boosters, but some scientists don't think they're needed for everyone. NPR science correspondent Joe Palca is with us. Good morning, Joe.
JOE PALCA, BYLINE: Morning, Noel.
KING: What are the arguments in favor of a booster?
PALCA: Well, the company points to data from Israel that, over time, its vaccine's ability to prevent disease begins to decrease. So the longer it's been since you've got vaccinated, the more likely you'll get a breakthrough infection, even a mild infection. And there's also some evidence that the vaccine's ability to prevent severe disease is declining, at least for people over 65, and that's more concerning. Then there's a paper from Israel out this week saying that the booster - a booster reduces the likelihood of any disease and severe disease. And finally, there's laboratory data where they look at people's blood over time to see if antibody levels are dropping. And they are, although exactly what that means for protecting someone from disease is not entirely clear. And there's also laboratory data that show a booster sends those antibodies back to high levels, and high antibodies generally mean more protection.
KING: OK. Given all of that, why are some scientists saying, not so fast?
PALCA: Well, the data showing that the vaccine efficacy is dropping is not all that strong. And immunologists like Marion Pepper at the University of Washington say, we shouldn't be talking about boosters until we see more breakthrough infections that are sending people to the hospital.
MARION PEPPER: I don't think we are yet. I need to see data right now that says a booster is essential 'cause so far I haven't seen it.
KING: OK, so there's that objection. And then some people have raised an ethical objection about giving Americans a booster shot.
PALCA: Yeah, many people around the world have no coverage at all. Here's Buddy Creech, the director of the Vanderbilt Vaccine Research Program.
BUDDY CREECH: There are still billions around the globe that have no access to vaccine. I think that has to go into our decision-making process.
PALCA: And to be clear, there's some serious outrage among countries that don't have the vaccine that wealthy countries are giving out boosters, and poorer countries can't get hold of vaccines for love or money.
KING: So when the FDA advisory committee meets today, what do you think is going to happen?
PALCA: Well, it should be a lively discussion. And remember, this is just an advisory committee. It's still up to the FDA to make the final decision. They could make it as soon as today, probably a few days from now. I'm guessing - and I'm prepared to be wrong, but I would say the advisory committee will say boosters are appropriate for some people, possibly older people or people with health conditions. Buddy Creech suggested a different possibility.
CREECH: Those who are front-line health care workers, those that are in long-term care facilities - they might require boosting if for no other reason than to keep people who are serving and who are at highest risk out of harm's way from even minor colds that could keep them out of work.
PALCA: Because Creech says the health care system is already showing signs of strain, and losing staff to illness would be bad.
KING: NPR science correspondent Joe Palca. Thank you, Joe.
PALCA: You're welcome. Transcript provided by NPR, Copyright NPR.
