ARI SHAPIRO, HOST:

Updated COVID vaccines are coming this fall, and they'll likely target a variant that's circulating now. That's the news out of a daylong meeting held by a panel of experts advising the Food and Drug Administration on vaccines. NPR's Pien Huang is here to tell us more about their decision. Hey there.

PIEN HUANG, BYLINE: Hey, Ari.

SHAPIRO: There is already a vaccine that targets the omicron variant, so what was the purpose of this meeting?

HUANG: You're right, Ari. The current version of the COVID vaccine essentially targets two versions of the virus. It's the original Wuhan strain and omicron subvariants that were circulating last fall. So this is the current bivalent vaccine.

But the problem is that the virus is constantly changing, so none of these versions are circulating now. So the question before the advisers today for the FDA was - does the vaccine need to be updated, and how so? - especially as we get to the fall, which is a time when there could be a surge as people start spending more time indoors.

SHAPIRO: And what was their decision?

HUANG: Well, everyone on the panel - there are 21 people on the panel, and everyone voted to update the vaccine to target a substrain of omicron. And there's probably going to be a few changes as a result.

So first, they've ditched the bivalent vaccine and are going forward with a monovalent vaccine, meaning it just targets omicron. And there was also a lot of discussion about which COVID strain to go with. So they saw three options, and they recommended one called XBB.1.5. That's a strain that's been dominant for a few months now, and it's the one that the manufacturers can get out the quickest. And all the strains they considered was pretty similar, so a vaccine for any one of them should work pretty well for the others.

SHAPIRO: You said they all voted for the update, but there was a lot of discussion. So were - like, were there any dissenters, any disagreement? How confident are they that this is the best strategy?

HUANG: Yeah, you know, it got feisty, and there was a debate on whether one yearly COVID shot is the right way to go forward. That's the strategy that we, as a country, use for seasonal flu, but COVID hasn't really settled into a seasonal pattern yet. Some of the doctors on the panel said maybe we should keep it flexible. We might need a shot more frequently or less frequently, depending on how things evolve. But Dr. Peter Marks at the FDA pushed back.

(SOUNDBITE OF ARCHIVED RECORDING)

PETER MARKS: Now, I hate to be contrarian, but, you know, from a public health perspective, people need to be able to understand what we're actually doing. And there's only so fast that our manufacturers can actually change things.

HUANG: He was saying that, practically speaking, companies making a new version of the COVID vaccine and a few hundred million doses of it - going forward, it's really only going to happen once a year.

SHAPIRO: Would this shot be recommended for everyone or just, like, more vulnerable groups?

HUANG: That's still an open question. I mean, everyone is not at equal risk. So the CDC shared some data today that shows that, since last April, hospitalizations and deaths from COVID have been low in most groups. They have been disproportionately high in people who are over 75, so this might be a group that needs extra protection. Those with health issues like diabetes or chronic lung diseases - they may also have higher risks. But it's not clear at the moment whether this is going to be a shot that everyone should get or just specific groups.

SHAPIRO: So what is the process? What are the next steps going to be?

HUANG: So the FDA is going to take a few days to consider the committee's discussion. They're probably going to issue an official recommendation soon, which is going to give the vaccine-makers an OK on which variant to go with and a path to follow. The CDC will also weigh in a little bit later. And so when you sort of put that together, the new vaccines should be out in the fall, probably by around late September or early October.

SHAPIRO: Just in time for back to school. NPR's Pien Huang, thank you.

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

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