SCOTT DETROW, HOST:
The Pfizer vaccine is more than 90% effective at protecting young children against COVID-19. That is according to just released analysis the company has also sent to the Food and Drug Administration. The document is a big step toward something parents have been desperate for - shots in kids as young as 5. And it comes the morning after the Centers for Disease Control broadened out booster shot eligibility to people who have received any of the three approved vaccines. Joining us now is NPR health correspondent Rob Stein. Hey, Rob.
ROB STEIN, BYLINE: Good morning, Scott.
DETROW: So we've all become experts in our own minds on vaccine efficiency over the past year or so.
STEIN: Yeah, (laughter) not true.
DETROW: You more than others. But 90% - really good, it seems.
STEIN: Yeah, yeah. The FDA, you know, this morning posted this 81-page analysis that Pfizer and its partner BioNTech filed with the agency. This is to try to win authorization for their vaccine for kids ages 5 to 11, and the company says the vaccine appears to be more than 90% effective at preventing symptomatic COVID-19 among these younger kids. That's from the main clinical study that the company conducted, testing a 10-microgram dose. That's about a third of the dose used for adults and older kids. The lower dose was picked to minimize the risk for side effects but still generate a strong immune response. And the company says it did. The lower dose vaccine produced an antibody response comparable to the ones seen in people ages 16 to 25.
DETROW: That 90% rate, does that reflect the much more contagious delta variant?
STEIN: Oh, yeah. That's a good question. Yes. In fact, the company says that most of the cases of COVID-19 that occurred during the period of this study occurred in August and September, when delta was the dominant strain in the U.S.
DETROW: You talked about side effects. I know a lot of parents are worried about that, especially with kids on the younger end of the spectrum. What is the company saying?
STEIN: Pfizer says there don't appear to be any new safety problems with young kids, you know, when they get the company's vaccine. No cases of heart inflammation were seen in the main study, and that's that very rare side effect that Pfizer and Moderna vaccines can cause in younger men. Now, it's important to note that the company study only involved a few thousand children, so that kind of rare problem probably wouldn't be detected in a study that size. But the company estimates that any risk for that heart problem would be outweighed by protecting kids from getting that complication from getting COVID itself.
DETROW: Got it. So what happens next?
STEIN: The FDA will release its own analysis later today, and this is all for that meeting of FDA outside experts who will convene next Tuesday. They'll pore through all the scientific data and make a recommendation to the agency about whether to authorize the Pfizer vaccine for kids ages 5 to 11. The CDC takes this up the following week, so a vaccine for younger children could finally become available for elementary and middle school kids soon after that. Young kids will need two doses 21 days apart, just like their parents. But all this means 28 million elementary and middle school kids could well be on their way to being fully vaccinated by Thanksgiving.
DETROW: It would be very big news for holiday travel.
STEIN: Yeah. Oh, for sure.
DETROW: One more thing that happened - last night, the CDC fully approved boosters. Tell us about that.
STEIN: Yeah, that's right. The CDC's now signed off on boosters for many recipients of all three vaccines, the Moderna, the Johnson & Johnson and the Pfizer. Anyone 65 and older or at risk because of health problems or risky jobs or living situations who got fully vaccinated with the Moderna or Pfizer vaccine at least six months ago can now get a booster. And anyone who got the one-shot J&J vaccine at least two months ago is eligible, too. So this means tens of millions of people who got any of the three vaccines can now get boosters. And the CDC says it's OK for people to mix and match which vaccine they get as a booster. Any eligible Pfizer or Moderna recipients can get either of those for their booster. They seem to work about equally well. And anyone who got the J&J can go with any vaccine, too.
DETROW: Rob Stein, NPR's health correspondent. Thank you so much.
STEIN: You bet, Scott. Transcript provided by NPR, Copyright NPR.