SCOTT SIMON, HOST:
COVID vaccine boosters are now available to all adults in the United States. That's after an eventful Friday where the Food and Drug Administration authorized boosters for people 18 years of age and older and an advisory committee to the Center for Disease Control and Prevention supported that decision. This should clear up the confusion over who can get the booster and who should get one. We're joined now by NPR science correspondent Joe Palca. Joe, thanks for being with us.
JOE PALCA, BYLINE: You bet, Scott.
SIMON: We kind of compressed the details at the top, so let's back up to the FDA authorization. What did they actually decide about boosters?
PALCA: Well, they expanded the list of who was eligible, basically said anyone 18 and older - or older who had their first two shots of the Moderna or Pfizer vaccine could get a booster six months after the second shot, after completing the first round. And anyone who had had the Johnson & Johnson vaccine could get a booster two months after their first shot. Remember, that's a one-shot vaccine.
SIMON: And we should note boosters had already been available to people 65 years of age and older, and some were qualified for other reasons who were below that age.
PALCA: Yes. Before, only people at high risk for severe COVID, either because of their age or because of an underlying health condition or because of their jobs, were authorized to receive a booster. And it's been up to the CDC to define exactly what health conditions or which jobs are putting someone at high risk for severe COVID. And they did that a few weeks ago, but there was a long list of categories, and it was a little confusing about who was actually eligible, and it led to a lot of head-scratching.
SIMON: Did the CDC advisory committee do much to clear up that confusion?
PALCA: Well, basically, yes. I mean, there was a telling moment during the three-hour-plus advisory committee meeting when the members heard from Dr. Nirav Shah. He's director of Maine's Center for Disease Control & Prevention and the president of the Association of State and Territorial Health Officers (ph). And he said he'd been on a call with all the state health officers the day before, and they all said that they favored expanding the definition of who was eligible and clarifying and simplifying the rules.
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NIRAV SHAH: Individuals who right now are absolutely eligible for boosters are not able to parse the guidelines to come to that conclusion on their own.
PALCA: So Shah's words seemed to resonate, but the committee still wanted to make a distinction between who should get the vaccine and who may get the vaccine. Anyone 18 and older may get the vaccine. Anyone 50 and older should get the vaccine.
SIMON: So for people who now find themselves in a new position to consider getting a booster shot, are there any drawbacks?
PALCA: Well, not really. So far, the experience has been that there's no worse side effects reported with the booster. And there's no clear indication that the booster makes you more susceptible to one of the rare side effects, such as this heart inflammation known as myocarditis. So basically, no, it doesn't seem to be a problem.
SIMON: And ahead of the holidays, COVID cases reportedly are rising in most states. Will boosters be able to make much of an impact on that?
PALCA: Well, that's not clear. I mean, maybe fewer people going to the hospital - that's a good thing - fewer people dying - that's definitely a good thing. And there's some evidence that boosters might reduce the rate of transmission. If you do get a so-called breakthrough infection, it may be less likely that you would transmit that to somebody else. But everyone agrees - everyone still agrees that the best way to keep the coronavirus at bay is to get everyone vaccinated, and nobody's quite clear how to convince everybody that that's what should be done.
SIMON: NPR's Joe Palca, thanks so much.
PALCA: You're welcome. Transcript provided by NPR, Copyright NPR.