Pfizer and BioNTech have asked the Food and Drug Administration to authorize their COVID-19 booster shot to all people 18 and older.
The companies say the request is based on results from a study of more than 10,000 volunteers that show vaccine efficacy of 95% or greater for people receiving the booster.
The two companies made a similar request in September, but at that time a committee of independent experts that advises the FDA on vaccine matters voted against it.
Instead, the committee recommended that the vaccine be offered to people older than 65 and younger people at increased risk of a severe case of COVID-19 because of an underlying medical condition, a job or a living situation.
The results of the companies' booster study were not available to the committee when it offered its recommendations.
According to the Centers for Disease Control and Prevention, nearly 25 million people in the United States have received a COVID-19 booster shot, or about 13% of the U.S. population. More than 30% of people 65 and older have received a booster.
It's not entirely clear how many more people would qualify for a booster if the FDA grants the Pfizer-BioNTech request.
The "underlying medical" conditions that already make some eligible for a vaccine are rather broad: people with mental health conditions, smokers or former smokers, people who are overweight or obese to name a few.
Jobs in high risk settings are also fairly broadly defined: first responders, teachers, day care workers, manufacturing workers and grocery store workers are among those covered.
A third dose of the vaccine was made available to certain immunocompromised people in August.
Anecdotal evidence suggests that many drugstores providing the boosters are not scrupulous in making sure people fall into one of the authorized categories.
The FDA has not scheduled a meeting of its independent advisory committee for November, suggesting the agency may make a decision on the Pfizer-BioNTech on its own without seeking external advice.
AILSA CHANG, HOST:
Drug makers Pfizer and BioNTech have asked the FDA for authorization to provide their COVID-19 vaccine boosters to anyone 18 and older. Right now the authorization applies to certain adults, like those 65 and older or those with underlying health problems or other risks. Joining us now to discuss the reason for this request and whether it's likely to be granted is NPR science correspondent Joe Palca. Hey, Joe.
JOE PALCA, BYLINE: Hi, Ailsa.
CHANG: Hi. OK, so why are Pfizer and BioNTech asking for this expanded authorization now in particular?
PALCA: Well, last month they got some results from a large study of 10,000 people that looked at the vaccine as a booster and looked to see whether it was safe and whether it was effective. And the answer was, yes, it's safe, and it doesn't seem to cause unusual side effects. And, yes, it's effective - more than 95%. So they think they have an argument.
CHANG: Wait. But didn't Pfizer and BioNTech already ask for approval for anyone 18 or older earlier this year? I feel like this is deja vu right now.
PALCA: Yes, you've been studying your history. Yes. At the time, back in September, they asked the committee - they asked for approval for anyone 18 and older. And the FDA had an advisory committee that looked at this request. And they said, no, we're not convinced that we have that much data that can - that makes us think for sure that this is valuable.
But now there's the study I just mentioned. And there's also a lot of data coming out of Israel on the long-term efficacy of the Pfizer-BioNTech vaccine. And it's become clear over time that the vaccine loses some of its oomph when it comes to preventing illness. Presidential health adviser Anthony Fauci says when the data first started coming in, it looked as if the loss of protection might be restricted to older people. But more recent results suggest it's more pervasive than that.
ANTHONY FAUCI: Because the waning of immunity that the Israelis are seeing really extends not only to the elderly but even to the younger age groups.
CHANG: Interesting. OK, so have younger people in Israel been getting booster shots? And has it had any benefit?
PALCA: Yes. And Fauci says the experience with giving booster shots to adults of all ages in Israel has been very encouraging.
FAUCI: It diminishes the likelihood of both infection and severe disease when compared to the people who've received the standard two doses without the booster.
PALCA: And Fauci says what's particularly encouraging is that these studies came at a time when the delta variant was the dominant variant in circulation. And so it seems as if this vaccine booster works well against delta. And that's, of course, very encouraging.
CHANG: Very encouraging. I mean, ultimately, Joe, how important will boosters be to bringing the pandemic under control, you think?
PALCA: Well, you know, it'll certainly be helpful in preventing some illness and preventing some hospitalization. But I spoke with Eric Rubin, the editor of the New England Journal of Medicine, and also, he's also an adviser to the FDA. And I asked that same question of just how important these boosters will be.
ERIC RUBIN: From a public health standpoint, what's really important is to get vaccines to the people who aren't vaccinated yet. That's what's going to have an impact.
CHANG: OK. Well, then how soon will the FDA make a decision on this?
PALCA: Well, you know, the FDA's track record has been pretty fast in the last few months or this past year in terms of making a decision once these applications come in. And the indication is they haven't asked for a special advisory committee meeting. So it seems like they might be willing to make a decision on their own and fairly soon.
CHANG: That is NPR's Joe Palca. Thank you, Joe.
PALCA: You're welcome, Ailsa. Transcript provided by NPR, Copyright NPR.