But when it comes to long COVID, a medical condition in which symptoms of COVID-19 persist for weeks or even months after the acute infection clears, much remains unclear. Anecdotal reports that some so-called long haulers feel better after getting the COVID-19 vaccines have sparked a new line of research, as scientists explore whether immunization can treat — or even prevent — long COVID.
Long COVID Can Be Debilitating
As the highly infectious new omicron variant spreads, causing spikes in COVID-19 case counts, questions about long COVID are becoming more urgent. “An estimated 10 to 30 percent of people who have COVID-19 go on to have long COVID,” says Alba Azola, MD, assistant professor of physical medicine and rehabilitation at Johns Hopkins Medicine in Baltimore and codirector of the Johns Hopkins Post-Acute COVID-19 Team. Although there is no universally accepted definition of long COVID, certain symptoms often occur. “The most common symptoms are fatigue, brain fog, inability to remember — a lot of neurological symptoms,” says Akiko Iwasaki, PhD, professor of immunobiology and molecular, cellular, and developmental biology at the Yale School of Medicine in New Haven, Connecticut. Shortness of breath, cough, chest or stomach pain, headache, and joint pain also top a long list of potential symptoms of long COVID, according to the Centers for Disease Control and Prevention. The condition is a serious one. “Long COVID can be really debilitating,” says Dr. Iwasaki. “People have lost their jobs, some people are unable to get out of bed, and some people have very severe symptoms that just prevent them from doing the things they normally do. Simple things like taking a shower can be a huge task for them.” Even people with mild or asymptomatic COVID-19 can get long COVID. “It can happen to anyone,” Iwasaki says. “It’s really scary to think about healthy young people getting long COVID and no longer being able to think clearly, work, and be productive.” RELATED: Meet the COVID-19 “Long Haulers”
Some Long Haulers Say They Feel Better After Vaccination
Early in 2021, Iwasaki began seeing tweets from people with long COVID who experienced improvement in their symptoms after getting a COVID-19 vaccine. A survey published in April 2021 by Survivor Corps, a grassroots group of COVID-19 patient advocates and self-described “citizen scientists,” found that 42 percent of people with long COVID reported feeling better after getting a COVID-19 vaccine. In another patient survey, by the advocacy group LongCovidSOS, about 58 percent of respondents reported improvements in their symptoms after vaccination. These surveys suggest that many — but not all — people with long COVID will have a positive response to the vaccine. “They may have lost some symptoms, maintained others, so it’s not a complete cure, but nevertheless, there’s often an improvement after vaccination,” says Iwasaki. Dr. Azola finds the effect of vaccination to be “a little bit of a mixed bag.” As a physician who has followed long COVID since April 2020 and shares info with doctors at a nationwide collaborative of long-COVID clinics, she has seen a range of responses to immunization in patients. “Some report improvements,” she says, “and some report flares in symptoms” that typically last for one or two weeks. Others say that vaccination had no impact on their symptoms at all. RELATED: Brain Fog: A COVID-19 Symptom That May Linger
Researchers Dig Into Possible Explanations
Iwasaki is currently a principal investigator of the Yale COVID Recovery Study, an ongoing project designed to measure changes in immune response and long COVID symptoms before and after COVID-19 vaccination. The research includes all three COVID-19 vaccines available in the United States: Pfizer-BioNTech, Moderna, and Johnson & Johnson’s Janssen. “We decided to look at the scientific basis for what patients were reporting,” says Iwasaki. In addition to collecting information about a patient’s symptoms and medical history, researchers take blood and saliva samples to gather information about antibodies and T cells (both components of the immune response) in order to understand how each person reacts to the vaccine. “By doing this, we can correlate changes in the immune response to the changes that people with long COVID are experiencing in their symptoms,” Iwasaki says.
Why Do the COVID-19 Vaccines Seem to Help Some People With Long COVID?
Researchers haven’t pinpointed why the vaccines appear to ease long COVID symptoms in some individuals, but there are a couple of theories. “There may be remnants of virus that are persisting in some tissues that are driving chronic inflammation,” Iwasaki says. “If that’s the case, then the very robust antibody and T cell response that the vaccine induces may be able to clear the pathogen or reservoir of the virus.” If this theory is correct, then that process would lead to people feeling better and potentially even having a complete recovery, Iwasaki adds. Another possibility is that a COVID-19 infection can trigger an autoimmune reaction in the body. “If that’s happening, the vaccine may be making people feel better because it’s able to induce certain types of cytokines that can impact these autoreactive cells,” Iwasaki says. Cytokines are molecules produced by the body that help mediate an immune response. In that scenario, the improvement in symptoms would most likely be temporary because those cytokines don’t last very long, Iwasaki says.
Does Vaccination Protect You From Long COVID if You Have a Breakthrough Infection?
Although vaccination reduces your chances of getting COVID-19, it isn’t clear if it protects you from long COVID if you do get sick. “There are very conflicting results on that,” Iwasaki says. One study, published in September 2021 in The Lancet, showed that fully vaccinated individuals who developed a breakthrough infection were 49 percent less likely than unvaccinated people to report symptoms of long COVID (meaning symptoms lasting at least four weeks after infection). On the other hand, a preprint study (which has not yet been peer reviewed) posted on medRxiv on November 8, 2021, compared more than 9,000 vaccinated people with COVID-19 to the same number of unvaccinated people, and it found that the vaccine offered no reduction in the risk of long COVID.
What If You’re Unvaccinated and Get COVID-19?
“There is research to suggest that in unvaccinated people who get COVID-19, if you vaccinate these people early enough, their chance of getting long COVID is reduced,” says Iwasaki. These findings come from another preprint study, this one posted on November 18, 2021, which used data from Arcadia Data Research, a de-identified clinical and operational data set containing more than 150 million patient records. Investigators analyzed data from more than 240,000 people who had been infected with COVID-19, looking at different factors that could influence the development and progression of long COVID. “They found that people who got the vaccine zero to four weeks after getting COVID-19 were at a much lower risk of getting long COVID, compared with people who got the vaccine later,” says Iwasaki.
Experts Agree: Get The COVID-19 Vaccine
“I would definitely encourage people to get the COVID-19 vaccine, even if you’ve already been infected with COVID-19, not only to prevent reinfection but also to reduce your chances of getting long COVID,” says Iwasaki. Azola agrees, saying, “I always encourage my patients with long COVID to get vaccinated because there is always a chance that they will get some improvement.” She also advises patients who continue to have symptoms to advocate for treatment. “It’s hard right now because there are not enough post-COVID clinics, and the medical system is still learning about this condition,” she says. The fact that some of the tests on long haulers don’t reveal the specific underlying pathology or cause doesn’t mean there’s nothing wrong with these patients or that it’s “all in their head,” Azola emphasizes. “If you have long COVID, know that we are working to try to understand what is causing your symptoms and how to best treat you. I think that’s the most important thing for people to know,” she says.
