An estimated 10% to 30% of people who get COVID-19 suffer from persistent symptoms of the disease, or what is known as ‘long COVID’.
Judy Dodd, who lives in New York City, is one of them. She was plagued with headaches, shortness of breath, extreme fatigue, and problems with her sense of smell for nearly a year, among other symptoms.
She said she was concerned that this “slogging through life” would become her new normal.
Everything changed after she got her COVID vaccine.
‘I was like a new person. It was the craziest thing ever, ”said Dodd, referring to how many of her health problems significantly resolved after her second injection.
As the US pushes to get people vaccinated, a curious benefit emerges for people with this post-illness syndrome: Their symptoms subside and in some cases disappear completely after vaccination.
It is the latest clue in the immunological puzzle of long COVID, a still poorly understood condition that causes some to become infected with a variety of symptoms months after the initial illness.
The idea that a vaccine designed to prevent the disease can also treat it has sparked optimism in patients, and scientists studying post-disease syndrome are scrutinizing these stories.
“I didn’t expect the vaccine to make people feel better,” said Akiko Iwasaki, an immunologist at the Yale School of Medicine who studies COVID.
“More and more I started to hear that people with long COVID symptoms were reducing their symptoms or recovering completely, and then I started to get excited because this could be a potential cure for some people.”
While promising, it is too early to know how many people with long-term COVID feel better as a result of vaccination and whether that amounts to a statistically meaningful difference.
In the meantime, Iwasaki and other researchers are starting to include this question in ongoing studies of long-range aircraft by monitoring their symptoms before and after vaccination and collecting blood samples to study their immune response.
There are several leading theories as to why vaccines could relieve the symptoms of long-term COVID: it is possible that the vaccines clean up leftover viruses or fragments, interrupt a harmful autoimmune response, or otherwise ‘reset’ the immune system.
“It’s all biologically plausible and, more importantly, it should be easy to test,” said Dr. Steven Deeks of the University of California-San Francisco, who is also studying the long-term effects of the coronavirus on patients.
Stories from patients offer hope
Before she got the vaccine, Dodd, who is in her early 50s, said she felt like she was 20 years old.
She struggled to return to work, and even simple tasks gave her a devastating headache and exhaustion.
“I’d go up the subway stairs and stop at the top, take off my mask to get some air,” Dodd said.
After she received her first dose of Pfizer vaccine in January, many of Dodd’s symptoms flared up, so much so that she almost didn’t get her second dose.
But she did – and a few days later she found that her energy was back, that she was breathing easier, and soon even her problems with the smell disappeared.
It was as if the sky had opened. The sun was shining, ”she said. “It’s the closest thing to pre-COVID.”
In the absence of large studies, researchers are getting all possible information from patient stories, informal surveys and clinicians’ experiences. For example, about 40% of the 577 long-covid patients contacted by the Survivor Corps group said they felt better after vaccination.
In Dr. Daniel Griffin at Columbia University Medical Center in New York, “brain fog” and gastrointestinal problems are two of the most common symptoms that seem to resolve after vaccination.
Griffin, who is conducting a long-term study of post-COVID disease, initially estimated that about 30% to 40% of his patients felt better. Now he believes the number could be higher as more patients get their second dose and see further improvements.
‘We are doing a bit of settlement here [long COVID] by treating every symptom, ”he said. “If it is really true that at least 40% of people recover significantly after a therapeutic vaccination, then this is the most effective intervention we have had for a long time with COVID to date.”
A small UK study, not yet peer-reviewed, found that about 23% of long-term COVID patients showed an “increase in symptom resolution” after vaccination, compared to about 15% of those who were not vaccinated.
But not all clinicians see 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 – or none at all – have reported feeling better after vaccination, but it was not a widespread phenomenon.
“I’ve heard anecdotes of people feeling worse, and you can think of a scientific explanation why it’s going both ways,” said UCSF’s Deeks.
Why do patients feel better?
There are several theories as to why vaccines could help some patients – each relies on different physiological conceptions of long COVID, manifesting in different ways.
“The clear story is that long COVID is not just one problem,” said Dr. Eric Topol, director of the Scripps Research Translational Institute, which is also studying COVID and the potential therapeutic effects of vaccination.
Some people have a fast resting heart rate and cannot tolerate exercise. Others suffer mainly from cognitive problems, or a combination of symptoms such as exhaustion, sleep problems and problems with smell and taste, he said.
As a result, it’s likely that different therapies will work better for some versions of long COVID than others, Deeks said.
One theory is that people infected with the coronavirus never clear up completely, and maintain a viral ‘reservoir’ or fragments of the virus in parts of the body and cause inflammation and long-lasting symptoms, said Iwasaki, the Yale immunologist.
According to that statement, the vaccine could trigger an immune response that gives the body extra firepower to fight back the remaining infection.
“That would actually be the easiest way to get rid of the disease, because you get rid of the source of inflammation,” said Iwasaki.
Griffin of Columbia Medical Center said this idea of ”viral persistence” is supported by what he sees in his patients and what he hears from other researchers and clinicians. He said patients seem to improve after receiving one of the COVID vaccines, generally about “two weeks later when it appears they are having an effective, protective response.”
Another possible reason some patients improve is the understanding of COVID long as an autoimmune disease, in which the body’s immune cells end up damaging their own tissues.
A vaccine could hypothetically activate the “innate immune system” and “moderate symptoms,” but only temporarily, said Iwasaki, who has studied the role of harmful proteins called autoantibodies in COVID.
This self-defeating immune response takes place in a subset of COVID patients while they are sick, and the autoantibodies produced can circulate months later. But it’s not yet clear how that might contribute to long COVID, said John Wherry, director of the Institute for Immunology at the University of Pennsylvania.
Another theory is that the infection “ miswired ” the immune system in a different way and caused chronic inflammation, perhaps like chronic fatigue syndrome, Wherry said. In that scenario, the vaccination could somehow ‘reset’ the immune system.
With more than 77 million people fully vaccinated in the US, it’s hard to tell how many of those with a long COVID would have improved even without any intervention.
“At the moment we have anecdotes; we would like it to be true. Let’s wait for real data, ”said Wherry.
This story is part of a partnership that includes NPR and KHN.
Kaiser Health News (KHN) is a national health policy news service. It is an editorial independent program of the Henry J. Kaiser Family Foundation that is not affiliated with Kaiser Permanente.