STEVE INSKEEP, HOST:
How much risk is there really with the Johnson & Johnson vaccine now? The Food and Drug Administration told the company to apply a warning label. It says some people may face a risk of a rare neurological disorder in the weeks after vaccination. NPR science correspondent Joe Palca is following the story. Hey there, Joe.
JOE PALCA, BYLINE: Hey, Steve.
INSKEEP: So the warning says it could happen within 42 days of getting the vaccination. And I myself was counting back and trying to remember if my past - and I'm past the 42 days, by the way. But what is the neurological disorder here?
PALCA: It's called Guillain-Barre syndrome. And so far, it's only been associated with the Johnson & Johnson vaccine. But when I say - OK, so first let me tell you what it is. It's an autoimmune disorder. That means that a person's own immune system damages nerves. And it can cause muscle weakness and sometimes paralysis. Most people fully recover. Some have permanent disability. And some have even died. Nobody's quite sure what causes it. It has been associated with vaccines in the past, including the swine flu vaccine back in the '70s. But the connection and the why and exactly why - how it works is not clear.
INSKEEP: I guess we should note - right? - millions of people have taken the J&J vaccine, and we're talking about a very small additional number of cases than would normally be found in the general population. Is that right?
PALCA: That's exactly right. The signal is small. It's above background, which is the general population rate of getting this, which people do get from time to time. But that's why FDA said, hey, we see this signal. We think there might be a connection. We can't say for sure. But I have to tell you, Steve, that every COVID-19 expert I've talked to says definitely take the vaccine. The risk of Guillain-Barre syndrome is really small. And the risk of getting sick and dying from COVID-19 is much higher. And I know that people aren't calculating machines. And, sometimes, risk is only one of the factors they weigh in making decisions. And if you want proof of that, just look at all the people who buy lottery tickets.
PALCA: But a rational choice at this point is to take the vaccine.
INSKEEP: Well, let's talk about some of the other ways that people are having to reconsider how well-protected they are. People have had to think about the delta variant and whether their vaccine takes care of them there. People have had to think for some time about whether they might need a booster shot at some point. And now Israel this week is saying it's time for a third dose of vaccine with people - for people with compromised immune systems. Why would they take that step?
PALCA: Right. So this isn't for everybody, but you have to realize that vaccines work by training a person's immune system to recognize a virus, in this case, the coronavirus. But people with compromised immune systems - that could be people with a disease or people with - just taking immune-suppressing drugs because they have transplanted organs, and they don't want to reject the organs. So those are the two kinds of ways you can get a compromised immune system. And Dorry Segev is a transplant surgeon and researcher at Johns Hopkins.
DORRY SEGEV: We know that the protection that transplant patients are getting is much lower than that of people with normal immune systems. So then the question is, what do we do next? And it's not uncommon in transplantation for us to give extra doses of vaccines to our transplant patients.
PALCA: And the extra dose can sometimes provide that immune response that would protect them from a particular virus.
INSKEEP: Joe, this seems kind of straightforward. Give a little extra vaccine to people who might need a little extra vaccine. Is the United States doing this?
PALCA: Well, not yet. Israel, as you said, France has been doing it. And some patients in this country are doing it privately. And Dorry Segev has been studying some of them. And for some, it has prompted the kind of immune response that would protect someone from COVID-19 but not for everyone.
SEGEV: I don't think that a third booster dose is necessary for every single immunosuppressed patient. I don't think that a third dose will necessarily be the solution for every immunosuppressed patient. But that's a good place to start. And we need to understand the impact of these and the safety of doing these.
PALCA: And he's about to launch a study that will get some answers to that question.
INSKEEP: In about a sentence, should other people expect to get a booster sometime?
PALCA: It's possible. Federal officials are still saying not yet. But the companies - especially Pfizer has been pushing on the government to approve or at least authorize a third dose. So we'll see.
INSKEEP: Joe, thanks for the update.
PALCA: You bet.
INSKEEP: NPR's Joe Palca. Transcript provided by NPR, Copyright NPR.