RACHEL MARTIN, HOST:
Mondays seem to be the day we end up getting good news on vaccines. A couple weeks ago, the biotechnology company Moderna announced early results from the study of its experimental vaccine. And today, they're announcing fuller results, which concludes that their vaccine is 94% effective. We've got NPR's science correspondent Richard Harris with us this morning. Hi, Richard.
RICHARD HARRIS, BYLINE: Good morning.
MARTIN: Good morning. So some good news. What makes today's news, though, different from what we already heard?
HARRIS: Yeah. Well, it's a little hard to keep track, but Moderna had previously released analysis of some early results from its study. Now it has a lot more data from a study of 30,000 people, half of whom got the vaccine and half of whom got a placebo. They announced this morning that the vaccine was 94% percent effective in protecting people from COVID-19. Dr. Stephen Hoge, who's the president of Moderna, says the news is even better when it comes to severe cases.
STEPHEN HOGE: There were 30 cases on placebo and zero cases that were on the vaccine. So it looks like in the trial, we've been 100% effective at preventing severe COVID-19, which is really what's driving the burden of disease in hospitals and ultimately straining our public health systems.
MARTIN: OK, so a fuller picture of the effectiveness of this vaccine. So what happens now?
HARRIS: Well, Moderna has also collected a lot of data about safety and side effects. And the company says that information is encouraging as well. So they say today, they will submit an application for emergency use authorization to the FDA. Here's Dr. Hoge again.
HOGE: They will get a good stack of paper, but they've been receiving paper almost continuously from when we started. They still have an important, solemn responsibility to review that data and develop an independent perspective on it. And that's not an easy piece of work to do on a short time horizon.
HARRIS: But Moderna expects that in a little more than two weeks, the FDA will be ready for a public meeting to discuss this data. And a vaccine could get the thumbs up shortly thereafter, presuming it passes, of course. Now, either this vaccine or the Pfizer vaccine, which is very similar, could become available in mid to late December.
MARTIN: Wow. So assuming the FDA does its review of this Moderna vaccine, decides that these vaccines are safe and effective, what's it going to be like to get one of these shots, whether it's the Moderna one or the Pfizer one or any other clinical trial that makes it through?
HARRIS: Yeah. Well, both have side effects like soreness and achy arm, some fever and even some flu-like symptoms. I talked to Dr. Carlos del Rio at Emory University, which is one of the many sites that tested out the Moderna vaccine. And he said the side effects were - that he saw, they were very similar to those that come with the shingles vaccine, which is to say not much fun.
CARLOS DEL RIO: The side effects are not very dissimilar. You feel terrible for a day or two, but then you're fine, right?
HARRIS: But that's the price of getting a vaccine that protects you in the case of COVID from a potentially deadly disease. But, you know, del Rio says it's a complication in administering the vaccine because people who get these symptoms might think the vaccine has actually given them COVID-19.
DEL RIO: We're going to have to do very good messaging to explain to people that this is not COVID. This is a side effect of the vaccine and it's OK to have it. It actually means that the vaccine is working.
MARTIN: So judging by the reports from the Moderna and the Pfizer studies, it looks like someone who is vaccinated is unlikely to get COVID. Does that mean that they won't spread the infection, Richard?
HARRIS: Yeah, well, that's an important question, and there is no answer as yet. Moderna says so far it's been focusing on people who have symptoms of COVID-19, and it will take some months to figure out whether people who got the vaccine may also have gotten infected, but they just don't have symptoms. So Carlos del Rio at Emory says it's possible that - that's something that needs to be straightened out.
MARTIN: All right. NPR science correspondent Richard Harris, thank you.
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