Breakthrough Infections, Long COVID And You : Short Wave In rare cases, the delta variant of the coronavirus is causing vaccinated people to get sick — so-called "breakthrough infections." Now researchers are asking: Could these infections lead to long COVID, when symptoms last weeks and months? Today, science correspondent Rob Stein makes sense of the latest data, explaining what we know so far about long COVID in vaccinated people.

Read more of Rob's reporting here:

Breakthrough Infections, Long COVID And You

  • Download
  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

MADDIE SOFIA, BYLINE: You're listening to SHORT WAVE from NPR.


Hey, everybody. Emily Kwong here with NPR science correspondent Rob Stein. Hey, Rob.

ROB STEIN, BYLINE: Hey there, Emily.

KWONG: Hey, so today, we're checking in on COVID long-haulers. These are folks with COVID symptoms that last weeks or months or folks who were getting better, but suddenly new symptoms emerge. And Rob, nowadays, doctors are starting to describe this condition as long COVID, right?

STEIN: That's right, that's right. It's not a really well-defined, well-understood condition, but they can show up in people with even mild symptoms. And I wanted to take a look into whether it's also a word for people who get COVID after they get vaccinated, these so-called breakthrough infections.

KWONG: Yeah, it's a good question. So people getting COVID despite the vaccine is pretty rare. The symptoms are usually mild, but we're learning that sometimes, even the mild cases can make you feel pretty bad for a few days, right?

STEIN: Yeah. So, you know, mild cases can make you feel pretty crummy. There's a big variation in what's considered a mild case. And, you know, 178 million people are now fully vaccinated in the U.S., as of September 12. The Centers for Disease Control and Prevention says more than 14,000 fully vaccinated people have been hospitalized or died from breakthrough infections. But the agency doesn't keep a running tally of asymptomatic or mild breakthroughs nationally, which have been increasing during the delta surge.

KWONG: Got it.

STEIN: But you know, it's really important to emphasize that far fewer of these cases result in hospitalizations or deaths. The vaccines are highly effective at doing the most important thing - keeping people out of the hospital and developing lethal symptoms. Nonetheless, researchers are concerned that even mild cases, including cases that come after vaccination, may result in lingering symptoms.

KWONG: Right, lingering symptoms, aka long COVID.

STEIN: Right.

KWONG: So another thing I want to talk about quickly - the Biden administration announced some pretty big news last week. They're ratcheting up efforts to get more people vaccinated. What's the latest on that?

STEIN: The president is ordering all companies with 100 workers or more to require their employees to get vaccinated or submit to regular testing. That affects some 80 million workers, and another 17 million health care workers at facilities that receive Medicare or Medicaid funding are also being required to get vaccinated. And federal workers and contractors will no longer have the option to test instead of getting the shots. And the hope of all this is to protect people from a virus whose long-term implications we're really still trying to understand.


KWONG: So today on the show, we turn the program over to you, Rob, for the latest research on this really specific question. Can breakthrough infections lead to long COVID? You're listening to SHORT WAVE, the daily science podcast from NPR.

STEIN: Like millions of other Americans, Kathleen Hipps thought she was safe after she got two Moderna shots last spring. So she figured she just had a summer cold when she got the sniffles in July. But then, she spotted a bottle of Vicks VapoRub.

KATHLEEN HIPPS: And I thought, oh, you know, this might be kind of good for my cold. So I opened it up, and anyone who's ever smelled Vicks VapoRub knows how pungent of a smell it is, and I couldn't smell it. And that's when I knew I had COVID.

STEIN: And sure enough, Hipps, a 40-year-old lawyer in Los Angeles with two young sons, tested positive.

HIPPS: I got very sick. I was very tired, very congested, could barely get out of bed. I couldn't work at all. I had to find colleagues to cover my work for me. And I just spent the next week basically in bed, completely isolated from my family.

STEIN: She never ran a fever, though, or got bad head or body aches. And she started feeling better after about a week, tested negative, and went back to working from home and caring for her family.

HIPPS: I thought I was completely recovered. And I was in my mom's new car, and all of a sudden, I felt burning, and I thought there was something wrong with her car. And I moved my foot around, and everywhere I was moving my foot, I could still feel this burning.

STEIN: And then her other foot started burning, too, like she was walking on hot coals.

HIPPS: And I've kept having this burning sensation in my feet, and I've learned that this is neuropathy, and this is a common symptom of long COVID.

STEIN: Long COVID - when COVID-19 patients' symptoms just won't go away, or new ones emerge just when they think they're all better. Hipps still gets that burning every day - tingling and numbness in her hands, too, sometimes so bad she can't push her baby's stroller and so bad she's afraid to drive. Her periods are really heavy, too. And her work tires her out so fast now, she has to take lots of breaks.

HIPPS: I'm really scared. I mean, I'm really scared that there are things that are going on with me that I'm going to have to deal with for the rest of my life.

STEIN: Now, the vaccines are still incredibly good at protecting people from getting really sick or dying and are still quite good at keeping most people from even catching the virus or even getting mildly ill. But breakthrough infections can happen, especially with the delta variant. And it's becoming increasingly clear that unvaccinated people can develop long COVID symptoms, too, even from mild cases. So doctors have started to wonder if that could happen to vaccinated patients like Hipps, too. Dr. Avindra Nath is studying long COVID at the National Institutes of Health.

AVINDRA NATH: We've seen that with the infection itself in the unvaccinated individuals, about 30% of those individuals continue to have these long-haul COVID symptoms. And so the concern is that, even if you are vaccinated, if you got the infection, you got the virus, going to do the exact same thing to these individuals, too. So I think it's a good question.

STEIN: A small Israeli study recently provided the first evidence that breakthrough infections could lead to long COVID symptoms. And more recently, a big British study found that 5% of people who got infected, even though they were fully vaccinated, experienced persistent symptoms.

NATH: I think it's a reasonable concern, but it's too early. I think we need to follow these patients. It's quite recent that they have been recognized, so at the moment, we really don't have that answer.

STEIN: Other infectious disease experts remain highly skeptical that long COVID from breakthrough infections are a big problem. Here's Monica Gandhi at the University of California, San Francisco.

MONICA GANDHI: Pathophysiologically, it's quite unlikely to get long COVID from a breakthrough infection.

STEIN: Because, Gandhi says, the immune response generated by the vaccine would prevent that from happening.

GANDHI: I think that it absolutely is not impossible, but I think pathophysiologically, it is less likely.

STEIN: And she noted that the big British study found vaccination cut the risk for long COVID in half. But other researchers are convinced the problem is significant.

DAVID PUTRINO: Categorically, I can say that we have already been seeing a handful of cases of long COVID from breakthrough infection.

STEIN: David Putrino studies long COVID at Mount Sinai.

PUTRINO: We need to behave as though there is the same chance as always of developing long COVID from a mild to asymptomatic infection because, you know, once you have it, you can't unring that bell, and you're looking at months to years of illness.

STEIN: Putrino is working with Akiko Iwasaki, an immunologist at Yale, to try to understand how it could happen. Iwasaki says long COVID may be caused in some people from the virus hiding in the body. In others, it may be their immune systems overreact to the virus, a so-called autoimmune response.

AKIKO IWASAKI: We know that the vaccine induces a robust immune response to quickly clear the virus during breakthrough infections. And even with that, we're seeing some people develop long COVID. And that suggests to me that autoimmunity may be the culprit there.

STEIN: But even if breakthrough infections can lead to long COVID, others say there are plenty of other reasons vaccinated people should continue being careful to avoid catching the virus. Dr. Carlos del Rio is an infectious disease doctor at Emory.

CARLOS DEL RIO: At the end of the day, my biggest concern is - honestly, it's not that I'm going to get long COVID. It's I'm going to bring COVID and give it to somebody else, right? I have a young granddaughter. I can give it to her. I'm more concerned that the people who are vaccinated can get infected and transmit to others.

STEIN: For her part, Kathleen Hipps hopes her symptoms don't plague her for months or even years.

HIPPS: It's scary because, you know, there's obviously a lot of things we don't know about this virus, and I'm scared about these long-term implications on my body.

STEIN: But Hipps is still really glad she got the vaccine. She knows it might have kept her out of the hospital and kept her alive.


KWONG: Yeah, Rob, so after doing all of this reporting, how do you feel about where we are?

STEIN: Well, you know, Emily, the whole reason I decided to look into this in the first place is this has long been one of my pet worries - you know, that after hiding in my attic for more than a year, I'd end up with long COVID, even though I'm fully vaccinated. But the bottom line is the vaccines are still amazingly effective. And really, the only way out of this mess - getting more people vaccinated. But they're not perfect. So even people who are fully vaccinated like me still have to be careful. I have to wear my masks and avoid crowded places, especially where there might be a lot of unvaccinated people.

KWONG: Yeah. It's a really important message. We need all these strategies to combat the pandemic. So Rob, thank you so much for bringing that reminder to us, and this reporting, too.

STEIN: My pleasure, Emily.

KWONG: This episode was edited by Joe Neel and Gisele Grayson. Rebecca Ramirez was the producer, and Berly McCoy checked the facts. I'm Emily Kwong, and you're listening to SHORT WAVE, the daily science podcast from NPR.


Copyright © 2021 NPR. All rights reserved. Visit our website terms of use and permissions pages at for further information.

NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.