STEVE INSKEEP, HOST:
We started this week with the Pfizer vaccine arriving at sites across the United States and the country's first COVID-19 vaccinations. We are ending this same week with the likely authorization of a second vaccine. So many people need protection so quickly from coronavirus that it is considered essential to have more than one. And a panel of outside advisers to the FDA yesterday gave its judgment of the Moderna vaccine. They talked it over for hours in public on a video link - good for transparency. And NPR's Joe Palca was listening in. Hey there, Joe.
JOE PALCA, BYLINE: Hi, Steve.
INSKEEP: So was it a close call as the panel looked at the risks and benefits of this vaccine?
PALCA: No, it was the exact opposite - a slam-dunk. They voted 20-0 with one abstention in favor of the saying the vaccine was - the benefits would clearly outweigh the risk. I mean, they did talk about it for hours. They picked apart all sorts of issues. That - but that's what these panels are supposed to do. And as the meeting was drawing to a close and people were still raising interesting hypothetical questions that could be important about the Moderna vaccine - questions that unfortunately don't yet have answers - Paul Offit reminded his fellow committee members they should keep an eye on the big picture. Offit is a vaccine researcher at the Children's Hospital of Philadelphia.
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PAUL OFFIT: The question that's being asked us is, do we have enough evidence in hand to say that the benefits of this vaccine outweigh what, at the moment, as far as severe safety issues, are theoretical risks? I think the answer to that question is clearly, yes. I mean, the question is never, when do you know everything? It's, when do you know enough?
INSKEEP: So what are the clear benefits, Joe?
PALCA: Well, the clear benefits seem to be that if you give this vaccine to people, it will protect them from getting COVID illness. In this large study of 30,000 volunteers, 94% of the time, the vaccine was protective. And that was across age groups, across ethnic groups, across racial groups. So that's a very good success rate - better than officials had hoped for to begin with. And it was also extremely effective at preventing severe disease, although, again, the numbers were a little bit small. They - there were only 11 cases of severe disease that they were able to analyze.
And there's an indication that the vaccine might also help prevent transmission. And the idea is that people - well, they - not only will they not get sick, but they won't get infected because some people, of course, get infected but don't show any symptoms. But if that's the case, they could be transmitting the virus. And there's some indication that this vaccine might prevent that.
INSKEEP: Oh, goodness, well, that is a good thing to keep in mind - the possibility that somebody might be vaccinated but still be a carrier for this. You're saying this vaccine, at least in some of the early evidence, might be able to prevent that. With all of that said, of course, you've got 30,000 people who were involved in this study, and some people had things go wrong. What are some of the risks, as far as the panel knows?
PALCA: Well, the most tangible risks, I guess you'd say, were the reactions to the injection. I mean, a lot of people had a sore arm. They had muscle aches. They had fever. They had all sorts of things. Some - in some cases, they're saying, you know, if you get this vaccine, you might lose a day of work because you feel lousy. But in a way, that's the vaccine working because what it's doing is it's mounting an immune response as if it were infected by a virus. But after a day or so, the immune system realizes, well, wait a minute; there's no virus here, and it sort of stops doing its I'm-sort-of-infected thing. And so that's the most immediate.
The longer term, it's a little unclear. I mean, there were - in these 30,000 people, there were four cases of something called Bell's palsy, which is a temporary facial paralysis - three cases in the vaccine group, one in the placebo group. And the question is, well, you know - did these just happen by chance? - which they do - or was it related to the vaccine? So they'll be monitoring that.
And of course, we've been hearing in the Pfizer vaccine that there were some severe allergic reactions right after the shot. There were none of those right after the shot in the Moderna trial. But they'll want to make sure that's not happening when the vaccine gets rolled out and given to many people, assuming it will be.
INSKEEP: Joe, I'm glad you mentioned the long term because, of course, with any medicine, you would want to have long-term studies of its effects. We have here a case of three months or so of results, but scientists might like to have six months or a year or two years or five years. Is it going to be hard ever to get that long-term information?
PALCA: Well, yes and no. I mean, there are all sorts of plans to follow people and record their outcomes and, you know, have them report adverse events. But what they may not have are these randomized controlled clinical trials. I mean, right now there are still people who are getting - they've gotten shots, and they don't know whether they were vaccine or placebo. And those blinded - so-called blinded trials are the most effective for answering the question, is this thing we're seeing related to the vaccine or not?
But as people learn that there are vaccines available, they may leave the trial. And the committee spent a lot of time - panel spent a lot of time discussing, well, how can we get around that, or can we get around that? And Marion Gruber, who's with the FDA, says the agency prefers the kind of trial - this randomized controlled trial when making decisions about whether to greenlight a new drug or vaccine.
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MARION GRUBER: At the same time, we do realize that it may, at a certain point, not be longer feasible.
INSKEEP: May not be feasible to have a control group anymore - not safe for them. But very briefly, when will the FDA make its real decision about emergency use authorization?
PALCA: Right. Well, you know, it could be soon. They issued a statement yesterday saying to the Centers for Disease Control and Operation Warp Speed, you know, get ready to execute your plans for timely vaccine distribution. So something appears to be on its way.
INSKEEP: Joe, thanks very much.
PALCA: You're welcome.
INSKEEP: NPR's Joe Palca. Transcript provided by NPR, Copyright NPR.