FDA Advisers Endorse Pfizer COVID Booster Only For Those 65 And Over Or At Risk

MARY LOUISE KELLY, HOST:

Pfizer's request to offer a third dose of its COVID-19 vaccine to all Americans 16 or older ran into strong headwinds today.

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KATHLEEN HAYES: Dr. Perlman voted no. Dr. Gans voted no. Dr. Meissner voted no. Dr. Levy...

KELLY: Well, of outside experts that advises the FDA about vaccines - voted 16 to 2 against Pfizer's request. Then, it turned around and endorsed an alternate plan.

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HAYES: Dr. Perlman - yes. Dr. Gans - yes. Dr. Meissner - yes.

KELLY: NPR's Joe Palca listened to the panel's eight-hour virtual meeting today. He survived, and he joins us now to tell us what happened.

Hey, Joe.

JOE PALCA, BYLINE: Hey, Mary Louise.

KELLY: What is this alternate plan that the panel did endorse?

PALCA: Well, as you said, Pfizer was asking for a modification of their license that would allow them to offer the COVID vaccine - a booster shot of the COVID vaccine to anyone 16 and older at least six months after they completed a two-dose regimen. But Paul Offit of the Children's Hospital of Philadelphia captured what a lot of people were thinking.

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PAUL OFFIT: We're being asked to approve this as a three-dose vaccine for people 16 years of age and older without any clear evidence that a third dose for a younger person when compared to an elderly person is of value. If it's not of value, then the risks may outweigh the benefits.

PALCA: And so they - instead of the panel endorsing it, they endorsed an alternate proposal that said the booster dose should be offered to anyone 65 or older, as well as anyone at high risk of severe disease either because of some health condition or because their jobs put them in harm's way, such as health care workers.

KELLY: And walk us through some of the data that they were considering. What were the main points in favor of approving the booster?

PALCA: Well, there's a lot of laboratory data that says that the antibody levels over time go down and that if you give a booster shot, a third shot, you can send those antibody levels up to where they were right after the second dose, when you were presumably highly vaccinated. Then there was also data from Israel that showed that the people who were vaccinated a long time ago were more likely to have what - you know, these breakthrough infections, and in some case, severe breakthrough infections as compared with people who have been vaccinated more recently, suggesting that the vaccine's protection was wearing off.

KELLY: And what about the case against, like when we heard Paul Offit just there talking about - that the risk may outweigh the benefits?

PALCA: Well, you know, with any kind of a vaccine, you want to make sure that what you're getting is worth putting - I mean, there's no risk of being hurt by a vaccine if you don't take it, so there's always that to consider. And you want to make sure you're getting something for putting yourself at any kind of risk at all. And they just felt that the benefit wasn't there and the risk was small, but not completely insignificant. And more to the point, it wasn't really well characterized. And so they wanted to see more data.

KELLY: So worth remembering, this was not the FDA decision. This was the decision of a panel of outside experts that advises the FDA. What happens now?

PALCA: Well, I think what's going to happen is the FDA is going to have a good long think about this. I don't think this is the outcome they were expecting. It sounded like they were going to issue an emergency use authorization for this amended proposal. But then there's also a committee that advises the CDC, and they will weigh in later in the week, and they could have some recommendations about who they think should get this vaccine and under what circumstances.

KELLY: NPR's Joe Palca.

Thank you, Joe.

PALCA: You're very welcome. Transcript provided by NPR, Copyright NPR.