Scientists look at the progress made toward understanding — and treating — long COVID

ARI SHAPIRO, HOST:

It's one of the biggest medical mysteries to emerge from the coronavirus pandemic. Why do some people get over COVID while others are plagued with chronic symptoms for months or even years? This week, researchers came together to take stock of the progress science has made towards understanding long COVID. NPR's Will Stone was there and joins us from Santa Fe, N.M. Hi.

WILL STONE, BYLINE: Hi, Ari.

SHAPIRO: Why was this long COVID meeting a big deal?

STONE: Yeah, this was really science in action. It's one of the first major gatherings of researchers from around the world focused on what's driving long COVID and potential treatments. It was held by the nonprofit Keystone Symposia. And because long COVID is such a wide-ranging disease - many different manifestations, affecting all kinds of organs and systems in the body - that's actually attracted researchers with all kinds of backgrounds. So this was a chance for them to get in a room, in many cases to meet in person for the first time and share their findings and try to chart a path forward.

SHAPIRO: And what does that look like? It seems like we've been hearing for years that scientists are chipping away at this.

STONE: Yeah, to be clear, Ari, there is still a lot of work to be done to understand the underlying causes of long COVID. There is no one test that a doctor can run and say, OK, you have long COVID. There isn't yet a single proven treatment for the condition. And I think hearing all of that can make things feel a bit hopeless, especially for the patients who are suffering from this condition. But I will tell you, from being here the last few days, there's a lot of energy going toward this. And one scientist I spoke to in the hallway during presentations was Akiko Iwasaki. She's at Yale University. And she said it's a fine balance, you know, moving fast on research and still being deliberate.

AKIKO IWASAKI: I totally understand how frustrated patients are. The reality of biomedical research is that it takes time. Even to get a protocol up and running, we have to get approval from the right regulatory agencies and all that. So we're trying very, very hard to do this as soon as possible.

SHAPIRO: So Will, where are scientists exactly in the process of getting to the root of long COVID?

STONE: So to sum it up, I'd say the scientific journey with long COVID started with first, simply recognizing it's a real medical condition that needs to be studied, then describing it, defining it, then generating theories about what could be driving the symptoms. And scientists have now gathered quite a bit of evidence on these different theories. Some of the prominent ones that have been discussed at this meeting - there's viral persistence. That's the idea that the coronavirus or parts of the virus hang out in the body after the acute illness. There's also lots of evidence showing immune dysfunction - autoimmunity in some patients. Another is that it seems some viruses people had before COVID - specifically the Epstein-Barr virus, which causes mono - are being reactivated, and the body's actually responding to that. There's also big interest in the consequences of inflammation - in particular, the role of small blood clots called microclots that can be observed in long COVID patients. So all of these theories are at play.

SHAPIRO: That's so many different theories. Any sense of which one is most likely?

STONE: Not yet, and it's important to note that none of these are necessarily mutually exclusive. Some can be interrelated. There's evidence some could be happening in some patients, not others. In fact, there was interesting research presented here indicating there could be differences between what's going on in female patients versus male patients. So the bottom line is scientists have these different lines of evidence about possible mechanisms. Which of those are actually driving the symptoms? - we don't really know yet. And, of course, the answer will have implications for treatment. Right now, treating long COVID is all over the place. There are now some targeted clinical trials starting up that will help test some of these theories about what's behind the disease.

SHAPIRO: NPR's Will Stone reporting from Santa Fe. Thanks.

STONE: Thank you.

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