ARI SHAPIRO, HOST:
An estimated 10- to 30% of people with COVID-19 have symptoms that last for months. And while scientists still don't fully understand long-haul COVID, some people who suffer from it are finding relief in a surprising way. They feel better after getting the vaccine. Health reporter Will Stone has this story.
WILL STONE, BYLINE: It was like she had aged 20 years. That's how Judy Dodd describes life after she contracted COVID. She got sick a year ago, when the first wave hit New York City. She survived, but she never felt the same.
JUDY DODD: Crushing fatigue, headaches, shortness of breath - you know, I'd climb the subway stairs every day. I'd have to stop up at the top, take my mask off and breathe, you know, just to get air.
STONE: Though her long COVID symptoms improved slightly over time, it was a struggle. Then, in January, she got her first vaccine.
DODD: For the next three weeks, I was miserable.
STONE: Fever, exhaustion, dizziness - so bad she even went to a cardiologist.
DODD: I mean, it was more than like, you know, a few days with a sore arm that people are talking about.
STONE: It seemed like the vaccine was making her long COVID worse. So when it came time for her second shot...
DODD: I literally - I felt like I was walking to the guillotine.
STONE: She went to the vaccine clinic but froze. A nurse sat down next to her.
DODD: ...And said, you know, we're actually seeing some people who feel better after their second shot. I was like, really?
STONE: She got the shot. The next few days were bad - headaches, fatigue. But then...
DODD: It was like the sky had opened up. The sun was out. I was like a new person. It was the craziest thing ever.
STONE: And it stayed that way for more than a month. Her energy is back. Breathing is easier. Even her sense of smell has improved. Other people with long COVID are also finding relief after vaccination. And they've been talking about it with Akiko Iwasaki, an immunologist at the Yale School of Medicine.
AKIKO IWASAKI: That's when I really started to get excited because this might be a potential cure for some people.
STONE: It's not clear how many people this has happened to. Iwasaki is starting a study, though, collecting blood samples from people with long COVID.
IWASAKI: Of how much immune response they had before the vaccine, after the vaccine and what changed - and we can even correlate those changes to the symptom improvement.
STONE: Scientists like Iwasaki have several theories. One is that some with long COVID never fully clear the coronavirus, that there's a viral reservoir or fragments of the virus in some parts of the body. If that's true, the vaccine might boost their immune response against the virus.
IWASAKI: That would be, actually, the very most straightforward way of getting rid of the disease because you're getting rid of the source of inflammation.
STONE: Another theory is that long COVID is like an autoimmune disease, where the body makes immune cells that end up doing damage. In that case, Iwasaki says the vaccine might give a jolt to the immune system, helping with symptoms, but it's probably only temporary. All these explanations might be true or none of them.
Dr. Steven Deeks at the University of California, San Francisco is also studying long COVID. He's intrigued by these reports.
STEVEN DEEKS: It's all biologically plausible and, importantly, should be easy to test.
STONE: But he doesn't think vaccines will help everyone with long COVID.
DEEKS: This is many syndromes, we suspect. It's possible, I think likely, that these different therapies will work better for some of the versions of the syndrome than others.
STONE: After all, some of Deeks' patients actually feel worse, not better, after getting vaccinated.
DEEKS: And you can scientifically come up with an explanation for it going in either direction.
STONE: What researchers do agree on is that this vaccine response could be a window into long COVID. Dr. Eric Topol studies long COVID at the Scripps Research Translational Institute. He says any leads are precious.
ERIC TOPOL: We have no treatment, and the vaccine is the first real candidate treatment. But we have nothing. That's why this is a desperate situation.
STONE: He thinks they'll have more answers on how the vaccine may help in the next few months.
For NPR News, I'm Will Stone.
SHAPIRO: And this story comes from NPR's partnership with Kaiser Health News. Transcript provided by NPR, Copyright NPR.
