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AstraZeneca's Latest Report Supports Effectiveness Of COVID-19 Vaccine


Just how effective is the AstraZeneca COVID-19 vaccine? It's been a big question after an independent monitoring board called out the company and questioned its vaccine results that were released Monday. AstraZeneca now has new data out, and it shows the vaccine appears to be safe, but slightly less effective than initially believed. Joining us with the latest, NPR science correspondent Richard Harris. Hi, Richard.


MARTIN: First off for this conversation, what should we remember about the AstraZeneca vaccine?

HARRIS: Yeah, it's been quite a saga. First of all, the vaccine is not available in the United States, but the company plans to ask the Food and Drug Administration to authorize it. It's been a really rough road, though. The company's initial studies done outside of the United States were so irregular that the FDA said it wanted fresh data before evaluating this product. The company announced that fresh data in a press release on Monday, and it looked quite good. The company reported that the vaccine was 79% effective in preventing disease and even better at preventing hospitalizations and deaths.

MARTIN: Right. But then on Tuesday, there were all these questions over those very results, right? What were the concerns?

HARRIS: Right. A review panel at the NIH had seen the data before it had been released and was concerned that AstraZeneca was essentially cherry-picking its results to make the vaccine look better than it was. It had advised the company to give a more complete report, but the company had ignored that advice. Then, in an extraordinary move, the NIH announced that this review panel had issues with the data and was displeased that AstraZeneca ignored its request.

MARTIN: So AstraZeneca released its latest data analysis. What are the findings?

HARRIS: Right. So last night, they finally rolled out the data that the advisory committee had requested all along. And as expected, it shows that the vaccine is still quite effective but not quite as good as the initial press release had said. The company says it was 76% effective in the latest study, not 79%. And it added that, you know, it is still processing some data, so those numbers could still change a little bit. But perhaps more important in this study, nobody who got the shot ended up in the hospital or died from COVID-19. So by that measure, it's right up there with the three vaccines that are already in use in the United States.

MARTIN: What does this mean overall for this particular vaccine?

HARRIS: Well, this vaccine is already widely used elsewhere in the world because many other countries have approved it. It's only at $4 a shot, and it doesn't need special handling. So really, it is ideal for global use. And it's also used widely in Europe, although regulators there, you may recall, paused its use for a short while while they sorted out a potential side effect that affected about 1 in a million vaccine recipients. So one huge question is how much damage AstraZeneca's numerous missteps have done to the reputation of this vaccine. People may lose some enthusiasm for it.

MARTIN: And what does that mean about its potential use here in the U.S.?

HARRIS: AstraZeneca still says it intends to seek FDA authorization for emergency use here, and that's likely to take at least a month, we expect. And presuming that the FDA doesn't find more issues with the company's data, that should go ahead. But, you know, we already have three vaccines in use and another one that could also be on its way. So it remains to be seen just how much Americans will see of this vaccine. AstraZeneca has said that it will have about 30 million doses available immediately and another 20 million doses within a month of approval. But, you know, that's still a small percentage of doses needed. So it may turn out that this vaccine may not end up being a major player here in any event.

MARTIN: All right. NPR science correspondent Richard Harris, thanks for all that clarification. We appreciate it.

HARRIS: Any time. Thank you. Transcript provided by NPR, Copyright NPR.

Award-winning journalist Richard Harris has reported on a wide range of topics in science, medicine and the environment since he joined NPR in 1986. In early 2014, his focus shifted from an emphasis on climate change and the environment to biomedical research.