What We’re Learning About Long COVID Symptoms And Their Causes

26:12 minutes

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If you’d like to participate in long COVID research, take this survey from the Patient-Led Research Collaborative.

Over the two years of the COVID-19 pandemic, one topic has been on many people’s minds: long COVID. Some people with COVID-19 have symptoms that last for weeks, months, and sometimes even years after their initial infection. 

Long COVID affects people in different ways. Some report debilitating fatigue or a persistent brain fog that makes it hard to concentrate. And for many long haulers, their ability to exercise and or perform simple daily tasks remains severely limited.

Are you struggling with long COVID? Here are resources our guests recommend:

There’s still a lot that we don’t understand about the underlying causes of these symptoms. No one knows why some people develop long COVID, while others don’t. But over the last two years, researchers have slowly accumulated more knowledge about the drivers of long COVID, and how to best treat it. 

Ira speaks with two people intimately familiar with long COVID: Dr. David Putrino, director of rehabilitation innovation at Mount Sinai Health System in New York, New York, and Hannah Davis, co-founder of the Patient-Led Research Collaborative based in Brooklyn, New York.

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Segment Guests

Hannah Davis

Hannah Davis is co-founder of the Patient-Led Research Collaborative in Brooklyn, New York.

David Putrino

David Putrino is the director of Rehabilitation Innovation at Mount Sinai Health System in New York, New York.

Segment Transcript

IRA FLATOW: For the rest of the hour we’re going to talk about a topic that should be on a lot of people’s minds but likely isn’t. I’m talking about long COVID. This is where folks who get COVID have symptoms that last for weeks, months, sometimes even years after their initial infection.

Much of the country has rolled back mask mandates, thinking we’ve moved on from COVID. But there is a group of people who may have to live with it indefinitely. It’s not over for them. Long COVID affects people in different ways. Some report debilitating fatigue or a persistent brain fog that makes it hard to concentrate. And for many long haulers, exercise and basic movement is not the same as it was pre-infection.

There’s still a lot we don’t understand about the underlying causes of these symptoms, or why some people develop long COVID while others don’t, or could even a mild case or a symptom-free case of COVID lead to more debilitating illness later in life? Over the last two years, researchers have slowly accumulated more knowledge about the drivers of long COVID and how best to treat it.

And that’s what we’re going to be talking about now. Joining me today are two people intimately familiar with long COVID. Let me introduce them– Dr. David Putrino, Director of Rehabilitation Innovation at Mount Sinai Health System in New York, New York. Welcome to Science Friday.

DAVID PUTRINO: Thank you for having me.

IRA FLATOW: And Hannah Davis, co-founder of the Patient-Led Research Collaborative. She’s based in Brooklyn. Hannah, welcome to Science Friday.

HANNAH DAVIS: Thanks. It’s great to be here.

IRA FLATOW: Nice to have you. Dr. Putrino, are you seeing a surge of new long COVID cases as a result of the Omicron surge?

DAVID PUTRINO: Absolutely. I think we’re certainly seeing more cases coming through as a result of the Omicron surge. But I would also point out that many individuals are only just starting to get care now from some of the initial waves of COVID-19. So it often takes a little while for patients to get to us once they’ve been ill.

IRA FLATOW: And have you been able to track it outside of the US in other countries?

DAVID PUTRINO: Absolutely. I mean, I think that Hannah’s work and the work of the Patient-Led Collaborative has been phenomenal at this. But certainly we’ve been tracking the literature that has been published in other countries and countries that have been putting out more work than the United States in actually trying to track across the entire country.

And the numbers are concerning. The most recent ONC report from the UK showed that an estimated 2% of the UK population has long COVID.

IRA FLATOW: That’s amazing. How likely are vaccinated and boosted people to get long COVID versus those who are not?

DAVID PUTRINO: This is a tough question to answer. We certainly know that there is emerging literature to suggest that perhaps your probability of going on to develop long COVID is reduced post-vaccine, but the most up-to-date data that has been published on this matter still places it at a pretty high percentage. So the most recent estimates would suggest that in breakthrough COVID infections– that is, COVID infections that are occurring in people who are fully vaccinated– there still appears to be around a 10% chance of going on to develop long COVID symptoms, which is very, very high.

IRA FLATOW: Wow. Yeah, wow. Let’s take a question from a listener who sent us one through our VoxPop app.

AUDIENCE: I’m Deb in Portland, Oregon. I’m curious about whether the rumors that I’ve heard about sometimes vaccinations helping people who have long COVID to kind of reboot their systems and have their symptoms improve– whether that’s true or not.

IRA FLATOW: What do you say?

DAVID PUTRINO: I think that’s a great question. The way that we’re currently viewing vaccinations and their role in long COVID symptoms is– I view of vaccination as a symptom modifier. So some people are experiencing worsening symptoms, other people are experiencing improvement in symptoms, and a larger majority of individuals don’t really see a change in their symptoms post-vaccination.

So this is interesting because it gives us some clue as to how some people with long COVID may have some immune underpinnings that are influencing their symptoms. And there’s some phenomenal work happening under the leadership of Akiko Iwasaki out at Yale University looking into this exact question. But right now I would not say that you can rely on a vaccine to improve your long COVID symptoms.

IRA FLATOW: This is Science Friday from WNYC Studios talking about long COVID with Hannah Davis and Dr. David Putrino. And Hannah, let me go to you. Why did you decide to start the Patient-Led Research Collaborative?

HANNAH DAVIS: So I’m a co-founder of it with four other patients who are, in some context, a researcher or data scientist or policymaker before getting sick. For us, we all got sick in March 2020, in the first wave. And at the time there were no answers for us. The CDC was still talking about this as something that didn’t affect younger people, that everyone would recover from in two weeks if they weren’t hospitalized.

And we had all gotten sick and were still sick, and in April 2020 were still sick, and really had no clue what was happening. There was no public communication. And so we all joined the Body Politic Support Group. And it’s on Slack, so there was a data nerds channel, so that really selected for people who are very curious and kind of looking for any data or any answer to explain what was happening to us.

And one woman, Gina Assaf, decided to make a survey of all of the patients at that time– several thousand patients who were experiencing these symptoms. And I joined right when they had collected the data. So I offered my skills– my background was in machine learning.

And we just wanted to get answers for ourselves at first, but at the time that was the only data available. So we started getting calls from the CDC, et cetera, and then decided to keep continuing the research.

IRA FLATOW: Why is it so important to have patients driving the research conversation?

HANNAH DAVIS: I think especially for under-researched and poorly understood illnesses, doctors’ hypotheses might not necessarily be the most accurate. Patients have the strongest understanding of the illness because they have lived experience of it. And this leads to knowing the right questions to ask and research. And so listening to patients and engaging in patient-led research helps speed research up overall because you can kind of focus on the areas that seem to be the biggest clues.

IRA FLATOW: Do you think that health care officials were sort of ignoring long COVID patients– long-haulers– from the beginning?

HANNAH DAVIS: Yes, definitely. I think one of the things that bothers me the most is that we actually have so much evidence, including in the last SARS, including other viruses– like EBV– that many, many viruses lead to long-term effects. You know myalgic encephalomyelitis, dysautonomia are really common post-viral conditions. And this should have been integrated into the pandemic response from the start, and that just didn’t happen.

IRA FLATOW: All right, we’re going to take a break. We want to hear more of comments that you have to make. We have a lot of people coming in on Twitter and on the phones. Our number– 844-724-8255, 844-SIDE-TALK– if you want to talk to our guests, Dr. David Putrino, Director of Rehabilitation Innovation at Mount Sinai Health System based here in New York, and Hannah Davis, co-founder of the Patient-Led Research Collaborative based in Brooklyn. 844-724-8255.

So many questions– we’ll see if we can get to as many of them as we can, because this is a topic we have to talk about. Stay with us. We’ll be right back after this break.

This is Science Friday. I’m Ira Flatow. If you’re just joining us, we’re talking about the phenomenon of long COVID with my guests, Dr. David Putrino, Director of Rehabilitation Innovation at Mount Sinai Health System here in New York, Hannah Davis, co-founder of the Patient-Led Research Collaborative. She’s based in Brooklyn, New York.

And I’m going to go to the phones, but before I do I want to bring up an interesting point I think that’s central to the issue here. And that is that the CDC recently relaxed mask guidelines, and many states across the country have followed suit. They’ve reverted back to pre-pandemic precautions as COVID seems to be going away. Dr. Putrino, should public health messaging and policies be more focused on long COVID?

DAVID PUTRINO: Yes. I mean in the strongest possible terms, yes. I think that from the outset, long COVID has been treated more like a shadow pandemic and less like an actual pandemic. People have not been giving it the level of attention it deserves as a mass disabling event in the United States. And the current sort of switch away from safe practice across the nation should be cause for alarm for everybody.

Long COVID is very much a continuing issue that we need to be strongly concerned about. And we still need to strongly get out the message that death is not the only serious outcome of COVID, especially non-hospitalized COVID cases– these so-called mild cases of COVID. There’s nothing mild about an acute case of COVID right now.


HANNAH DAVIS: I completely agree. I feel like the change to deprioritize masks just says that long COVID doesn’t matter, and it’s going to put so many people at risk who don’t even realize that they are at risk, honestly, in many cases, because there’s been such a lack of prioritizing and communicating about how serious long COVID is and how it can happen to anyone and completely change your life, possibly permanently.

IRA FLATOW: Let’s go to the phones– to in Harrisburg, Pennsylvania. Hi, Conor. Are you there? Hello? Who’s on the phone? All right. Let’s see– let’s hope we’re working the phones here and that they’re working. Let me go to– let’s see who else we can go to. Let’s go to Audrey in Fairfield. Hi, Audrey– are you there? Audrey, are you there? Hi, Audrey.

AUDIENCE: I’m here, I’m here. Yes.

IRA FLATOW: Hi, go ahead.

AUDIENCE: Hi. I have a unique situation. I have what’s called a prolonged concussion, which means I had two head injuries within six weeks. And I had COVID– my whole family had it– the first week of September, or the two weeks. I had all the symptoms of my concussion, which were migraines, I couldn’t remember things– it messes with your whole vestibular system. So I still have those side effects.

IRA FLATOW: Does your does your physician take these things seriously?

AUDIENCE: Yes. What ended up happening is– come the middle of October, November– I was losing memory, I was getting lost, my eyes were getting weak again, my migraines were unbearable. So I see two neurologists, and I also am in cognitive therapy, as well as eye therapy, which I had graduated from, but now I’m back in it. And my neurologist, as well as my eye doctor, have said there’s no research about this and they don’t know the long-term effects.


AUDIENCE: And that is very scary to me, and I don’t know if you know anything about that, or have you seen anything regarding concussions?

IRA FLATOW: Let me ask my guests. Hannah, Dr. Putrino.

HANNAH DAVIS: I would say that I am not sure what the impact of COVID is particularly on post-concussion syndrome, but long COVID is definitely very similar to post-concussion syndrome in that it causes many of the same symptoms that you just mentioned. I’m not sure if Dr. Putrino. Knows more than that.

DAVID PUTRINO: Yeah, thanks, Hannah. I would tend to agree. And first of all, I’m just so sorry for what you’re going through. It does sound very uncertain and quite frightening. What I would say is that many of the symptoms that we see with long COVID can be often associated with what we call dysautonomia, which is a part of the nervous system, called the autonomic nervous system, which controls a lot of things that are ordinarily under automatic control in the body getting knocked out of balance.

And we know that post-concussion syndrome often is also explainable by dysautonomia as well. And so it is very possible that you’ve experienced a flare of your existing dysautonomia as a result of your long COVID infection. Your physicians are correct in that we currently don’t have a lot of research in people who had post-concussion syndrome and then got COVID to say that this is precisely certainly what is happening. But it does sound like you’re getting good care and there’s a good chance that what we’re looking at is a worsening of your dysautonomia.

IRA FLATOW: Is it possible that you can develop long COVID symptoms without even knowing you have contracted COVID in the first place, Dr. Putrino?

DAVID PUTRINO: Absolutely. We know for a fact that your chance of contracting long COVID is not correlated with the initial severity of your symptoms. So we have certainly seen many individuals who had an asymptomatic course of COVID 19 infection go on to develop long COVID symptoms, which is incredibly alarming when we consider the fact that it’s hard enough right now to get insurers and other care providers to take long COVID seriously when you have a known case of COVID.

But if you are an unfortunate individual who had an asymptomatic case of COVID and was unable to test positive or develop antibodies– as we know that many people with COVID do not seroconvert– you may find yourself in a really tough situation.

IRA FLATOW: We have some tweets that are coming in. Shannon on Twitter asks, “If you’re not vaccinated, can long COVID effects be more serious or more likely?”

DAVID PUTRINO: Certainly more likely. We still don’t know all of the factors that contribute to severity of long COVID symptoms, but we certainly know enough now that if you’re unvaccinated your chances of developing long COVID-like symptoms are more like 30%.

IRA FLATOW: That’s– wow. Let’s go to the phones because we have lots of people who have questions. Let’s see if we go back to Conor in Harrisburg. Are you there, Conor?

AUDIENCE: Oh hey, how are you doing?

IRA FLATOW: Hey there, go ahead.

AUDIENCE: Oh, sorry. Long-time listener– I always enjoy listening to your show while at work. I have an interesting story. I’ll keep it short, but I had COVID when it first came out. My mother went on a business trip and she came back sick and she didn’t tell anybody. And I got it, and it hit me a lot harder than it hit her. And I was under covers for two weeks– all the symptoms, complete nightmare.

And as I was recovering– it was very, very slow process– I was on a hike and I got bit on my arm by a tick. And I didn’t think twice about it. And you know, I’ve probably been bitten by a tick many times before, but instead of my health slowly going towards normal, it is going the opposite direction. I’m just wondering– could there be a relation?

IRA FLATOW: Do you think you got Lyme disease– is what you’re saying?

AUDIENCE: Oh, no, I definitely have it. But–

IRA FLATOW: Did it did it affect COVID? Did it affect your long-hauling?


IRA FLATOW: Yeah, let me ask the doctors. Dr. Putrino, what do you think?

DAVID PUTRINO: We think about long COVID as an infection-associated illness, and some of the initial work that we’re seeing coming out of some phenomenal immunology research labs and, in fact, some of the work that we’re doing ourselves, is really pointing us toward the idea that many people with long COVID have changes to their immune system occurring.

And one of those changes can be that some of our immune system that deals with making sure that we generate antibodies to fight off dormant infections that we have in our body, as well as fighting off new infections, can be impaired. And so we often see reactivation of old infection-associated illnesses.

So many people who previously had Lyme disease, but it’s been quite dormant for some time, can experience worsening of Lyme symptoms. Epstein-Barr Virus is another very common virus that people are experiencing reactivations of. And the list goes on. There are many, many previous viruses that can be reactivated by the immune sequelae of long COVID.

IRA FLATOW: That’s really interesting. That’s something no one talks about. Something like herpes– things like that– cause a recurrence?

DAVID PUTRINO: Absolutely. Absolutely. Anything that was laying dormant can often be reactivated and we– I’m sure– you know I’d love to hear from Hannah, because she has way more data than we do, but I–

IRA FLATOW: Well, I’m going to go to Hannah. Let me just give us a break. This is Science Friday from WNYC Studios.

OK, Hannah, you’ve published two research papers tracking long COVID symptoms. What are the biggest takeaways here?

HANNAH DAVIS: So for us, I think that in the beginning we kind of helped show that long COVID wasn’t just respiratory symptoms– that it was kind of cognitive, neurological, systemic, immunologic, the reinfections like Dr. Putrino was just talking about.


HANNAH DAVIS: Our recent paper– one of the biggest findings for me– was actually that cognitive dysfunction and memory loss are in the top three frequent symptoms and happen as equally and 18 to 29-year-olds as in people over 60.


HANNAH DAVIS: And so in the beginning we heard a lot about brain fog, but we really showed that it impacts the ability to drive, to take care of your children, to communicate, and especially to work. We found that 2/3 of people had to either reduce their hours or quit completely. And that didn’t even include people who took early retirement because of COVID.

And then another really big thing we found was that, as Dr. Putrino mentioned, we have a very big issue with people who weren’t able to get tests in the first wave, and even in recent waves– you know, Omicron had a lot of testing and accessibility. The CDC estimates that only one in four COVID cases have confirmation.

So we actually accepted people that were symptomatic-positive and symptomatic-negative and then compared them. And we found that the major difference between the two cohorts was not actually in the symptoms– and this was looking at dozens of symptoms over time– but the date that they got tested after onset. So the positive cohort got tested at an average of day six. The negative cohort got tested at an average of day 43. And so we try to communicate to people that having a negative test doesn’t always mean they didn’t have COVID– it often means they weren’t able to access a test.

IRA FLATOW: This is Science Friday from WNYC Studios, talking with Hannah Davis and Dr. David Putrino. A tweet– this is a really interesting tweet from Maelstrom, who asks, “Are we going to have a huge population of people suffering debilitating symptoms?”

HANNAH DAVIS: I think so, definitely. I mean, from my perspective, there’s only a couple places in the world that are tracking long COVID, you know, at the population level, and one of them is the UK. And they have found right now 2.4% of the entire population has long COVID– and that includes 4% of teachers and health care workers. And that’s after two years of the pandemic.

And we know that recovery can happen in the first three months, and after that it’s less likely. And if you get diagnosed with something like myalgic encephalomyelitis or dysautonomia or a lot of these other kind of clotting conditions– there’s no evidence to show that it’s not lifelong. It’s likely lifelong in many of these cases. And every year, for disabling– you know, 1 and 1/2 extra percent of our population– which gets more vulnerable every year, because having a COVID infection in itself is a pre-existing condition. From my perspective, it looks pretty dismal.

IRA FLATOW: Wow. Let me get one last question in for time– Beth in Neptune, New Jersey. Hi, Beth.

AUDIENCE: Oh, hi. I’m sorry, I lost you for a minute. So I have sort of a complicated case which I will really try to be succinct about. I am hypothyroid since I’m two years old. I’m in my 60s now. And a lot of these symptoms mimic an underactive thyroid. And of course I’m medicated and under the care of an endocrinologist.

But I was in California President’s Weekend, when COVID was first starting, with my daughter. And she came back and was diagnosed with COVID. And I never was diagnosed with it. I never had specific symptoms, and I didn’t test for antibodies when I found out she had it. However, I can honestly say– and I’m a teacher, and my school started right back that September– so I’ve been in school for a long time with–

IRA FLATOW: Beth, I have to ask you to sum up what your question is.

AUDIENCE: So my question is, how do I know– is there any way to know if it’s my thyroid or COVID or long-term because all– I have symptoms of brain fog–

IRA FLATOW: OK, OK, I got you. Dr. Putrino, any answer to that?

DAVID PUTRINO: Thank you for sharing that story. I think you’ve raised a very important point, which is, at present, we do not have a good answer for you. It could be worsening of your thyroid condition or it could be the case, as we were discussing earlier in the segment, that you had an asymptomatic case of COVID that has led into long COVID.

What I can say is that we are working around the clock to try to come up with meaningful concrete biomarkers of long COVID that can allow us to diagnose long COVID beyond a clinical diagnosis based on symptoms, but we’re not quite there yet.

IRA FLATOW: All right, we have run out of time. So many questions, so little time to answer them. Dr. David Putrino, Director of Rehabilitation Innovation, Mount Sinai School of Medicine here in New York, Hannah Davis, co-founder of the Patient-Led Research Collaborative. She’s based in Brooklyn, New York. Thank you both for this valuable information today.

HANNAH DAVIS: Thank you so much for having us.

IRA FLATOW: You’re welcome. And if you want to find out how to join the long COVID support groups we’ve talked about or participate in the Patient-Led Research Collaborative survey, go to sciencefriday.com/longcovid. That’s sciencefriday.com/longcovid. Here’s Kyle Marian Viterbo with some of the folks who helped make this show happen.

KYLE MARIAN VITERBO: Thanks, Ira. Annie Nero is our individual giving manager. John Dankosky is our director of news and audio. Daniel Peterschmidt is our digital producer. And I’m community manager, Kyle Marian Viterbo. Thanks for listening.

IRA FLATOW: Thanks, Kyle. BJ Leiderman composed our theme music. Thank you all for listening. I’m Ira Flatow in New York.

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Shoshannah Buxbaum is a producer for Science Friday. She’s particularly drawn to stories about health, psychology, and the environment. She’s a proud New Jersey native and will happily share her opinions on why the state is deserving of a little more love.

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