A MARTINEZ, HOST:
Millions of Americans are now eligible to get booster shots of the Pfizer vaccine, but that's only if they had received Pfizer for their first two shots. And that has left many people who got the one-and-done Johnson & Johnson vaccine wondering, what about me? NPR's Will Stone has the story.
WILL STONE, BYLINE: Whichever shot you can get first - that's the one for you. This was the mantra of top doctors like Anthony Fauci back in the spring. It's why Amy, who teaches in Chicago, ended up with the Johnson & Johnson vaccine. But last month, she started to get nervous. The delta variant was surging, and she was hearing the J&J might not be as good.
AMY: I knew I was going to be back in the classroom. My parents are going to be moving into assisted living. It just seemed like there were lots of additional risks for me and lots of potential for me to infect vulnerable people.
STONE: She was also reading stories that millions of vaccines in the U.S. were going unused.
AMY: It seemed like I needed to get a second shot of something.
STONE: Her own doctor told her to wait. But other friends in the medical field told her to get one.
AMY: And the thing that I was able to get was a Pfizer.
STONE: This is an unauthorized booster. The FDA has not OK'd any booster for people who got J&J, so we're only using Amy's first name because she's worried about her employer finding out. But it wasn't like she had to get the shot in a back alley somewhere. She just walked into a drugstore.
AMY: They asked me if it was my first or second shot, and I said, yes, it's my first Pfizer shot and left it at that.
PAUL SAX: Many people with the J&J vaccine are getting tired of waiting.
STONE: That's Dr. Paul Sax at Harvard Medical School and Brigham and Women's Hospital. He says it was admirable for Johnson & Johnson to go for this one-and-done approach. But...
SAX: The bottom line is that one shot is probably not sufficient to generate sufficient antibody responses for protection against delta.
STONE: This is what some recent data from the CDC suggests - that the Johnson & Johnson vaccine is only about 70% effective against hospitalization. So Sax says it's reasonable for people, especially those who are more vulnerable to COVID, to get a second shot of Moderna or Pfizer.
SAX: I would counsel someone to strongly consider it and actually have done so, but, of course, we can't do that under official guidance right now.
STONE: He says, clearly, there are some unknown risks of rare side effects, but he thinks the chance of getting a bad case of COVID outweighs those. In fact, some hospitals in San Francisco are already offering a supplemental dose of the mRNA vaccines for people who got J&J. But Dr. Albert Shaw at the Yale School of Medicine is a bit more cautious.
ALBERT SHAW: I would generally not suggest that people kind of run out and do it themselves and wait for, I think, the best clinical studies to kind of reach a conclusion on them.
STONE: Shaw points to one study that isn't peer reviewed yet, looking at hundreds of thousands of insurance claims to see how J&J was holding up against severe illness.
SHAW: It looked like it did pretty well, and I think that's all reassuring.
STONE: The White House has said it hasn't forgotten about the approximately 15 million people who got Johnson & Johnson, but a recommendation on boosters could be a few weeks away. Johnson & Johnson has already given the FDA data showing a second shot of its own vaccine dramatically increases protection. And Dr. Bill Moss at Johns Hopkins University says mixing J&J with an mRNA booster may also create a strong immune response.
BILL MOSS: So this mixing, you know, looks very promising.
STONE: This is already being done in Europe with a vaccine similar to J&J. But getting that booster option through the U.S. regulatory process is going to take time. And in a pandemic, many people just don't want to wait.
Will Stone, NPR News.
(SOUNDBITE OF EVOCATIV'S "INTERLUDE") Transcript provided by NPR, Copyright NPR.