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Pfizer Concludes Coronavirus Vaccine Trial And Will Seek FDA Approval


With so much gloomy news about COVID-19, it is nice to be able to share some good news. A COVID-19 vaccine made by a partnership between the pharmaceutical giant Pfizer and the German biotech company BioNTech appears to be 95% effective in preventing disease. Now, that is almost identical to what Moderna reported for its COVID vaccine earlier this week. Here to talk about these latest results is NPR science correspondent Joe Palca.

Hey, Joe.


KELLY: Just to make clear we're talking about the same thing; this is the same Pfizer-BioNTech vaccine we were talking about last week...

PALCA: Yeah.

KELLY: ...That I thought was 90% effective?

PALCA: Yeah, yeah. Well, this - that was an interim analysis, but now the companies say they've reached the primary goal of their study. And when they got more data, they got a more clear idea of how well it worked. And the news earlier this week from Moderna was also just an interim analysis. So we'll probably be hearing more from them soon, too.

KELLY: So bottom line is it was good news from Pfizer, and now it's even better news that they're reporting.

PALCA: Yes. And the company said they needed to get at least 164 cases of COVID-19 among the participants to be reasonably sure that the results were real and not a statistical fluke, and they actually reported 170 cases. All but eight of those were in volunteers who got the placebo as opposed to vaccine, so the vaccine appears to be protecting most people. And scientists seem thrilled. For example, Paul Offit is a vaccine researcher at the University of Pennsylvania and a member of the committee that advises the Food and Drug Administration on vaccines. Here he is speaking earlier today at a COVID-19 vaccine analysis team briefing for reporters.


PAUL OFFIT: I think there is every reason to be enormously optimistic. I think, you know, as far as we know, they're highly effective for a short period of time against what appears to be a range of diseases, you know, from mild to severe disease.

PALCA: And these were large studies - more than 43,000 in the Pfizer case. That's the size a manufacturer might take to the FDA for approval.


OFFIT: The only difference is the length of the study is much shorter. But then again, it has to be. I mean, you're not going to study these vaccines for two or three years for a virus that's killed 250,000 people this year.

KELLY: Now, alas, Joe, it is, of course, our job to insert a little bit of skepticism into the enormous optimism, so let me ask. You know, that point we just heard Offit make about the length of the study is going to be way shorter - great, I'm all in favor of shorter and turning the corner on this pandemic. But there will be people hearing that and being worried, is it going to be safe?

PALCA: Well, I mean, yes, that's a concern. And so far, things are looking good. But it's a concern that the FDA is very well aware of, the companies are well aware of, and they intend to monitor that closely. And at that same briefing I mentioned, Norman Baylor raised another issue. Baylor is president and CEO of Biologics Consulting, and he's also the former director of FDA's Office of Vaccines Research and Review. And he says, yes, the vaccines are looking extremely promising, but those vaccines both use a kind of technology called mRNA. And making them on a large scale may turn up problems.


NORMAN BAYLOR: We don't know. There may be manufacturing issues that the FDA has identified because they've been getting data - real-time data on the manufacturing side.

PALCA: So Baylor thinks this is an issue the FDA might want to get advice from its committee of external advisers when it meets.

KELLY: So next step - what happens next?

PALCA: Well, Pfizer says it's going to apply for an emergency use authorization. That will allow it to distribute the vaccine as long as we're in a pandemic emergency. And the FDA will convene this advisory panel and consider that application.

KELLY: And real quick, when might people start getting a vaccine?

PALCA: Best case, end of December maybe. There's 25 million doses that - I mean, people Pfizer says it can provide vaccine to. And Moderna has another 10 million people it can help, so there you go.

KELLY: All right. NPR's Joe Palca.

Thank you, Joe.

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

Joe Palca is a science correspondent for NPR. Since joining NPR in 1992, Palca has covered a range of science topics — everything from biomedical research to astronomy. He is currently focused on the eponymous series, "Joe's Big Idea." Stories in the series explore the minds and motivations of scientists and inventors. Palca is also the founder of NPR Scicommers – A science communication collective.