NOEL KING, HOST:
All right. Joining us now is Dr. Celine Gounder. She's an infectious disease specialist at NYU. She's also a former adviser on the pandemic to the Biden administration.
Good morning, Dr. Gounder.
CELINE GOUNDER: It's great to be here.
KING: So you've dug into the data on COVID-19 boosters. Do you think they are needed? And if so, for whom?
GOUNDER: I think we have to be very specific about in whom they're indicated. And there is very good data from different countries that if you are immunosuppressed, if you are elderly and if you live in a long-term care facility - a nursing home, for example - that you would benefit from an additional dose of vaccine. And that is consistent in data from Israel, from the U.K., from Kaiser Permanente here in the United States that those are the groups that truly would benefit from an additional dose.
KING: What about people who got the single-dose Johnson & Johnson vaccine? I hear a lot of people saying if you only got one shot, you might need a booster more than someone who got two shots. Is there any science behind that?
GOUNDER: There is. We are seeing a higher rate of breakthrough infections and more severe disease as a result of that among people who got the Johnson & Johnson vaccine. I think it was laudable that they tried to come up with a single-dose vaccine that would be more acceptable to many people and still effective. But unfortunately, it just isn't playing out to be that way. And we're waiting on additional data to make the best recommendations as to what additional dose of vaccine that group would require.
KING: Is there any evidence that boosters can better protect vaccinated people from getting mild infections? Or are people who would get the booster going to get sick the way they did - they do with the vaccine, just not as severely as they would?
GOUNDER: I think it's really important that we reset expectations about what vaccines can or can't do. So if you give an additional dose of vaccine now, it would be normal for your antibody levels to spike but then to drop again. And so you could find yourself in a situation where you keep boosting and boosting and boosting just to prevent those milder breakthrough infections. And, in fact, Israel currently is looking at giving now fourth doses of COVID vaccine. And I just don't...
KING: Really?
GOUNDER: ...Think that's where we want to be going.
KING: OK. That's interesting - fourth doses. Does all of the debate around boosters and what I think you could legitimately call confusion in this country - does it worry you at all?
GOUNDER: Well, it does worry me in the sense that we haven't been very clear with the public about, what are we talking about when we talk about vaccine effectiveness? What are we actually trying to prevent? What is realistic given the vaccines that we have? And what's the end game here?
KING: Let me ask you about effectiveness 'cause I keep seeing this places, and I keep hearing people who are not experts make arguments based on this fact. So the CDC finds that the effectiveness of mRNA vaccines to stop a symptomatic infection has dropped just a little bit, from more than 90% effective to 80% effective. And you hear people saying, oh, my gosh; OK, this is a sign that we need to get everyone a booster. You take a look at that fact and you think what exactly?
GOUNDER: That's actually normal.
KING: OK.
GOUNDER: If your antibody levels didn't drop after every infection or vaccination, your blood would literally turn into a sludge of antibodies to all the infections and vaccinations you got over a lifetime. And so simultaneously to making antibodies, your immune system is also forming memories of that infection or vaccination in the form of memory cells. And those are poised to protect you against the virus later on. There's some time it takes for those to kick in. So you will have a breakthrough infection. But they protect you against severe disease, hospitalization and death.
KING: OK - a useful distinction. In the couple seconds we have left, do you think manufacturers are going to need to change the vaccine every year because this virus mutates?
GOUNDER: I don't think so. I think the vaccines that we have now are going to be sufficient.
KING: Dr. Celine Gounder, an infectious disease specialist at NYU, thank you so much for your time this morning.
GOUNDER: My pleasure. Transcript provided by NPR, Copyright NPR.