An estimated聽迟辞听of people who get covid-19 suffer from lingering symptoms of the disease, or what鈥檚 known as 鈥渓ong covid.鈥
Judy Dodd, who lives in New York City, is one of them. She spent nearly a year plagued by headaches, shortness of breath, extreme fatigue and problems with her sense of smell, among other symptoms.
She said she worried that this 鈥渟log through life鈥 was going to be her new normal.
Everything changed after she got her covid vaccine.
鈥淚 was like a new person. It was the craziest thing ever,鈥 said Dodd, referring to how many of her health problems subsided significantly after her second shot.
As the U.S. pushes to get people vaccinated, a curious benefit is emerging for those with this post-illness syndrome: Their symptoms are easing and, in some cases, fully resolving after vaccination.
It鈥檚 the latest clue in the immunological puzzle of long covid, a still poorly understood condition that leaves some who get infected with wide-ranging symptoms months after the initial illness.
The notion that a vaccine aimed at preventing the disease may also treat it has sparked optimism among patients, and scientists who study the post-illness syndrome are taking a close look at these stories.
鈥淚 didn鈥檛 expect the vaccine to make people feel better,鈥 said聽, an immunologist at the Yale School of Medicine who鈥檚 researching long covid.
鈥淢ore and more, I started hearing from people with long covid having their symptoms reduced or completely recovering, and that鈥檚 when I started to get excited because this might be a potential cure for some people.鈥
While promising, it鈥檚 still too early to know just how many people with long covid feel better as a result of being vaccinated and whether that amounts to a statistically meaningful difference.
In the meantime, Iwasaki and other researchers are beginning to incorporate this question into ongoing studies of long haulers by monitoring their symptoms pre- and post-vaccination and collecting blood samples to study their immune response.
There are several leading theories for why vaccines could alleviate the symptoms of long covid: It鈥檚 possible the vaccines clear up leftover virus or fragments, interrupt a damaging autoimmune response or in some other way 鈥渞eset鈥 the immune system.
鈥淚t鈥檚 all biologically plausible and, importantly, should be easy to test,鈥 said聽聽of the University of California-San Francisco, who is also聽聽on patients.
Patient Stories Offer Hope
Before getting the vaccine, Dodd, who鈥檚 in her early 50s, said she felt as if she had aged 20 years.
She had trouble returning to work, and even simple tasks left her with a crushing headache and exhaustion.
鈥淚鈥檇 climb the subway stairs and I鈥檇 have to stop at the top, take my mask off just to get air,鈥 Dodd said.
After she got her first dose of the Pfizer vaccine in January, many of Dodd鈥檚 symptoms flared up, so much so that she almost didn鈥檛 get her second dose.
But she did 鈥 and a few days later, she noticed her energy was back, breathing was easier and soon even her problems with smell were resolving.
鈥淚t was like the sky had opened up. The sun was out,鈥 she said. 鈥淚t鈥檚 the closest I鈥檝e felt to pre-covid.鈥
In the absence of large studies, researchers are culling what information they can from patient stories, informal surveys and clinicians鈥 experiences. For instance, about 40% of the 577 long-covid patients contacted by the group聽聽said they felt better after getting vaccinated.
Among the patients of聽聽at Columbia University Medical Center in New York, 鈥渂rain fog鈥 and gastrointestinal problems are two of the most common symptoms that seem to resolve post-vaccination.
Griffin, who is running a long-term study of post-covid illness, initially estimated that about 30% to 40% of his patients felt better. Now, he believes the number may be higher, as more patients receive their second dose and see further improvements.
鈥淲e鈥檝e been sort of chipping away at this [long covid] by treating each symptom,鈥 he said. 鈥淚f it鈥檚 really true that at least 40% of people have significant recovery with a therapeutic vaccination, then, to date, this is the most effective intervention we have for long covid.鈥
A small聽, not yet peer-reviewed, found about 23% of long-covid patients had an 鈥渋ncrease in symptom resolution鈥 post-vaccination, compared with about 15% of those who were unvaccinated.
But not all clinicians are seeing the same level of improvement.
Clinicians at post-covid clinics at the University of Washington in Seattle, Oregon Health & Science University in Portland, National Jewish Health in Denver and the University of Pittsburgh Medical Center told NPR and KHN that, so far, a small number of patients 鈥 or none at all 鈥 have reported feeling better after vaccination, but it wasn鈥檛 a widespread phenomenon.
鈥淚鈥檝e heard anecdotes of people feeling worse, and you can scientifically come up with an explanation for it going in either direction,鈥 said UCSF鈥檚 Deeks.
Why Are Patients Feeling Better?
There are several theories for why vaccines could help some patients 鈥 each relying on different physiological understandings of long covid, which manifests in a variety of ways.
鈥淭he clear story is that long covid isn鈥檛 just one issue,鈥 said聽, director of the Scripps Research Translational Institute, which is also studying long covid and the possible therapeutic effects of vaccination.
Some people have fast resting heart rates and can鈥檛 tolerate exercise. Others suffer primarily from cognitive problems, or some combination of symptoms like exhaustion, trouble sleeping and issues with smell and taste, he said.
As a result, it鈥檚 likely that different therapies will work better for some versions of long covid than others, said Deeks.
One theory is that people who are infected never fully clear the coronavirus, and a viral 鈥渞eservoir,鈥 or fragments of the virus, persist in parts of the body and cause inflammation and long-term symptoms, said Iwasaki, the Yale immunologist.
According to that explanation, the vaccine might induce an immune response that gives the body extra firepower to beat back the residual infection.
鈥淭hat would actually be the most straightforward way of getting rid of the disease, because you鈥檙e getting rid of the source of inflammation,鈥 Iwasaki said.
Griffin at Columbia Medical Center said this 鈥渧iral persistence鈥 idea is supported by what he鈥檚 seeing in his patients and hearing from other researchers and clinicians. He said patients seem to be improving after receiving any of the covid vaccines, generally about 鈥渢wo weeks later, when it looks like they鈥檙e having what would be an effective, protective response.鈥
Another possible reason that some patients improve comes from the understanding of long covid as an autoimmune condition, in which the body鈥檚 immune cells end up damaging its own tissues.
A vaccine could hypothetically kick into gear the 鈥渋nnate immune system鈥 and 鈥渄ampen the symptoms,鈥 but only temporarily, said Iwasaki, who has聽 of harmful proteins, called autoantibodies, in covid.
This self-destructive immune response happens in a subset of covid patients while they are ill, and the autoantibodies produced can circulate for months later. But it鈥檚 not yet clear how that may contribute to long covid, said聽聽director of the Institute for Immunology at the University of Pennsylvania.
Another theory is that the infection has 鈥渕iswired鈥 the immune system in some other way and caused chronic inflammation, perhaps like chronic fatigue syndrome, Wherry said. In that scenario, the vaccination might somehow 鈥渞eset鈥 the immune system.
奥颈迟丑听, teasing apart how many of those with long covid would have improved even without any intervention is difficult.
鈥淩ight now, we have anecdotes; we鈥檇 love it to be true. Let鈥檚 wait for some real data,鈥 said Wherry.
This story is part of a partnership that includes NPR and KHN.