ARI SHAPIRO, HOST:
The Food and Drug Administration today authorized the first updated COVID-19 boosters since the pandemic began. NPR health correspondent Rob Stein is with us with some details. Hi, Rob.
ROB STEIN, BYLINE: Hey there, Ari.
SHAPIRO: So what are these new boosters, and how have they been updated?
STEIN: These are new versions of the Moderna and Pfizer-BioNTech vaccines that have been reprogrammed to target both the original strain of the virus and - and this is the important part - the omicron variant. Specifically, they're designed to protect against the super contagious omicron subvariants that are infecting most people right now. So federal officials hope the new shots will shore up people's immunity, protect them against omicron better - especially as another surge of infections is expected to hit this fall and winter - and hopefully give people immunity that lasts longer than the original shots. They might even guard against new variants that emerge. Here's the FDA's Dr. Peter Marks.
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PETER MARKS: If I had to say what keeps me up at night most in this pandemic, it's that we have seen lots of twists and turns that were hard to predict. So it's the unknown unknowns that really are concerning. By doing this, we've tried to mitigate against that.
SHAPIRO: So how are these new boosters likely to work?
STEIN: You know, Ari, that's the big question. And unfortunately, no one really knows for sure. For the first time, the FDA is authorizing these vaccines based on tests in mice instead of people, combined with how people's immune systems responded to previous versions of the vaccines, including one targeting the original strain of omicron. The FDA says that leaves no doubt that, No. 1 the vax shots are safe. And No. 2, the new booster should cut the risk of catching the virus and getting COVID or long COVID. Here's Dr. Peter Marks again.
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MARKS: The public can rest assured that a great deal of care has been taken by the FDA to ensure that these updated boosters meet our rigorous safety, effectiveness and manufacturing quality standards.
STEIN: While many outside experts that I've been talking to agree, some are more skeptical.
SHAPIRO: Why is that?
STEIN: You know, no one's worried about safety. It's clear the vaccines are very safe. But critics say mouse studies just aren't very good at predicting how vaccines work in people. And earlier vaccines - the tests on those earlier vaccines indicate they're only a bit better than the original shots at best. And so the worry is people will think these new shots protect them more than they really do. Here's John Moore. He's an immunologist at Weill Cornell Medicine.
JOHN MOORE: There may be a modest benefit to protection against infection, but it will be modest, which is why I say don't believe that you're getting super strong shielding against infection.
STEIN: And Moore and others also worry that the fact that the vaccines were only tested in mice might make it even harder to convince people to get them. It's been a tough sell already, convincing people to get their first or second boosters, and there's still plenty of people out there who haven't gotten any shots. And that's the main reason between four and five hundred people are still dying every day from COVID.
SHAPIRO: I'm sure many people are wondering how soon they can get these new boosters. What's the schedule?
STEIN: Yeah. So the CDC will decide by the end of the week exactly who should get these new boosters and how they should be used once they become available next week. The FDA authorized the Moderna booster for anyone 18 and older and the Pfizer-BioNTech booster for anyone 12 and older. But some experts think the people who really need them are those at high risk, like older people and those with other health problems. Another big question is how long to wait to get the shots. The FDA says two months since the last shot is long enough, but others say that's too short, people should wait four to six months after their last shot or infection or the new boosters may not just work very well.
SHAPIRO: NPR's Rob Stein, thank you.
STEIN: You're welcome, Ari. Any time. Transcript provided by NPR, Copyright NPR.
