SCOTT SIMON, HOST:
As vaccines roll out, science rolls on. Researchers are now recruiting college students from more than 20 campuses for a study to answer a critical question about COVID-19 vaccines. It is, do these shots just protect the people who get them? Do they also protect the people around them by blocking the spread of the virus? We're joined now to talk about this new study by NPR science correspondent Richard Harris. Richard, good morning.
RICHARD HARRIS, BYLINE: Sure. Good morning, Scott.
SIMON: Before we launch into the study, let's try and step back to try to understand a basic concept. If a vaccine prevents you from getting sick, how could you still be at risk for spreading the disease after you've been vaccinated?
HARRIS: Right. Well, remember; a vaccine prompts your body to make antibodies that protect you from a virus. But, you know, this disease is so new we don't know exactly how this all unfolds. If you come in contact with the virus, you may get a small infection before the antibodies kick in to protect you. And during that time, you might even produce enough virus to spread it to other people.
The first round of vaccine studies established that vaccines protect you, but they didn't address the rest of that equation. Dr. Myron Cohen at the University of North Carolina Chapel Hill says that's what the study of college students is designed to do.
MYRON COHEN: So now this is kind of, like, really important cleanup hitting, you know? It's like, OK. Now we're going back and trying to do what we couldn't do the first round because this is a heavy lift.
SIMON: Richard, how will this study get at those questions?
HARRIS: Researchers on more than 20 college campuses will recruit students for this study. Half will get the COVID vaccine immediately, and the other half will get the shots four months later. Everyone will swab their noses every day, and those samples will be sent to a lab to look for signs of active virus. And, Scott, anybody who's actually shedding the virus will then be asked to go and ask their close contacts to volunteer for nose swabs, too. And all this will help researchers figure out to what extent vaccinated people can still get infected and shed the virus.
SIMON: Richard, if people can still get infected and shed the virus, why are we all still being asked to wear masks even after we've been vaccinated?
HARRIS: Well, we don't know the answer to that question, right? But that's what this study might provide an answer to. Cohen helped oversee the design of this study, and this is how he put it.
COHEN: At one point we talked about this as the maskless study, in some ways. If vaccines work unbelievably terrifically and so many people are vaccinated, maybe eventually we can reduce our dependence on masks. But we're a ways away from that.
HARRIS: Of course, this one study won't provide all the answers about masks and vaccines, but Cohen says it should be a really important line of evidence.
SIMON: And what else can we learn from this study?
HARRIS: Well, really, when you think of it, we still have a fair amount to learn about how this virus does its damage. I talked about the new study with Josh Schiffer, who's an infectious disease physician at the Fred Hutchinson Cancer Research Center in Seattle.
JOSH SCHIFFER: This has been portrayed as something that's going to help people make individual decisions. And that's true, but the greater implications are actually at the public health level.
HARRIS: He says if people can still spread the virus even if they're vaccinated, we will actually need to vaccinate more people to bring the epidemic under control through what's called herd immunity. On the other hand, if the vaccinated people rarely spread the virus, fewer people will need to be vaccinated to snuff out the epidemic.
SIMON: When will results be available?
HARRIS: Study organizers hope that they'll have answers in about five months. Of course, there are a lot of unknowns. For example, if vaccines become widely available to college students while the study is still underway, it's possible some participants will bail out. And that could hamper the research.
SIMON: NPR science correspondent Richard Harris, thanks so much.
HARRIS: Anytime, Scott. Transcript provided by NPR, Copyright NPR.
