How Well Do Vaccines Protect Against Long COVID?
Aug. 8, 2022 – New York City veterinarian Erin Kulick used to be a weekend warrior. Only 2½ years ago, the 38-year-old new mother played ultimate Frisbee and flag football with friends. She went for regular 30-minute runs to burn off stress.
Now, Kulick is usually so exhausted, she can’t walk nonstop for 15 minutes. She recently tried to take her 4-year-old son, Cooper, to the American Museum of Natural History for his first visit, but ended up on a bench outside the museum, sobbing in the rain, because she couldn’t even get through the first hurdle of standing in line. “I just wanted to be there with my kid,” she says.
Kulick got sick with COVID-19 at the start of the pandemic in March 2020, 9 months before the first vaccine would be approved. Now she is among the estimated one in five infected Americans, or 19%, whose symptoms developed into long COVID.
Kulick also is now vaccinated and boosted. Had a vaccine been available sooner, could it have protected her from long COVID?
Evidence is starting to show it’s likely.
“The best way not to have long COVID is not to have COVID at all,” says Leora Horwitz, MD, a professor of population health and medicine at New York University’s Grossman School of Medicine. “To the extent that vaccination can prevent you from getting COVID at all, then it helps to reduce long COVID.”
And just as vaccines reduce the risk of severe disease, hospitalization and death, they also seem to reduce the risk of long COVID if people do get breakthrough infections. People with more serious initial illness appear more likely to have prolonged symptoms, but those with milder disease can certainly get it, too.
“You’re more likely to have long COVID with more severe disease, and we have ample evidence that vaccination reduces the severity of disease,” Horwitz says. “We also now have quite a lot of evidence that vaccination does reduce your risk of long COVID – probably because it reduces your risk of severe disease.”
There is little consensus about how much vaccines can lower the risk of long-term COVID symptoms, but several studies suggest that number lies anywhere from 15% to more than 60%.
That might seem like a big variation, but infectious disease experts argue that trying to interpret the gap isn’t as important as noticing what’s consistent across all these studies: “Vaccines do offer some protection, but it’s incomplete,” says Ziyad Al-Aly, MD, chief of research and development at the Veterans Affairs St. Louis Health Care System. Al-Aly, who has led several large studies on long COVID, says focusing on the fact that vaccines do offer some protection is a much better public health message than looking at the different levels of risk.
“Vaccines do a miraculous job for what they were designed to do,” says Al-Aly. “Vaccines were designed to reduce the risk of hospitalization … and for that, vaccines are still holding up, even with all the changes in the virus.”
Still, Elena Azzolini, MD, PhD, head of the Humanitas Research Hospital’s vaccination center in Milan, Italy, thinks some studies may have underestimated the level of long COVID protection from vaccines because of limits in the study methods, such as not including enough women, who are more affected by long COVID. Her recent study, which looked at 2,560 health care professionals working in nine Italian centers from March 2020 to April 2022, focused on the risk for healthy women and men in their 20s to their 70s.
In the paper, published in July in TheJournal of the American Medical Association, Azzolini and her fellow researchers reported that two or three doses of vaccine reduced the risk of hospitalization from COVID-19 from 42% among those who are unvaccinated to 16% or 17%. In other words, they found unvaccinated people in the study were nearly three times as likely to have serious symptoms for longer than 4 weeks.
But Azzolini and Al-Aly still say that even for the vaccinated, as long as COVID is around, masks are necessary. That’s because current vaccines don’t do enough to reduce transmission, says Al-Aly. “The only way that can really help [stop] transmission is covering our nose and mouth with a mask,” he says.
How Vaccinations Affect People Who Already Have Long COVID
Some long COVID patients have said they got better after they get boosted, while some say they’re getting worse, says Horwitz, who is also a lead investigator at the National Institutes of Health’s flagship RECOVER program, a 4-year research project to study long COVID across the U.S. (The NIH is still recruiting volunteers for these studies, which are also open to people who have never had COVID.)
One study published in The British Medical Journal in May analyzed survey data of more than 28,000 people infected with COVID in the United Kingdom and found a 13% reduction in long-term symptoms after a first dose of the vaccine, although it was unclear from the data if the improvement was sustained.
A second dose was associated with another 8% improvement over a 2-month period. “It’s reassuring that we see an average modest improvement in symptoms, not an average worsening in symptoms,” says Daniel Ayoubkhani, principal statistician at the U.K. Office for National Statistics and lead author of the study. Of course, he says, the experience will differ among different people.
“It doesn’t appear that vaccination is the silver bullet that’s going to eradicate long COVID,” he says, but evidence from multiple studies suggests vaccines may help people with long-term symptoms.
Akiko Iwasaki, PhD, an immunobiologist at the Yale University School of Medicine, told a White House summit in July that one of the best ways to prevent long COVID is to develop the next generation of vaccines that also prevent milder cases by blocking transmission in the first place.
Back in Queens, NY, Kulick is now triple vaccinated. She’s due for a fourth dose soon but admits she’s “terrified every time” that she’s going to get sicker.
In her Facebook support group for long COVID, she reads that most people with prolonged symptoms handle it well. She has also noticed some of her symptoms eased after her first two doses of vaccine.
Since being diagnosed, Kulick learned she has a genetic condition, Ehlers-Danlos syndrome, which affects connective tissues that support skin, joints, organs, and blood vessels and which her doctors say may have made her more prone to long COVID. She’s also being screened for autoimmune diseases, but for now, the only relief she has found has come from long COVID physical therapy, changes to her diet, and integrative medicine.
Kulick is still trying to figure out how she can get better while keeping her long hours at her veterinary job – and her health benefits. She is thankful her husband is a devoted caregiver to their son and a professional jazz musician with a schedule that allows for some flexibility.
“But it’s really hard when every week feels like I’ve run a marathon,” she says. “I can barely make it through.”
