The COVID-19 vaccines have been a game changer for millions of people worldwide in preventing death or disability from the virus. Research suggests that they offer significant protection against long COVID.
False and unfounded claims made by some antivaccine groups that the vaccines themselves may cause long COVID persist and serve as barriers to vaccination.
To help separate the facts from falsehoods, here’s a checklist for doctors on what scientific studies have determined about vaccination and long COVID.
What the research shows
Doctors who work in long COVID clinics have for years suspected that vaccination may help protect against the development of long COVID, noted Lawrence Purpura, MD, MPH, an infectious disease specialist at New York–Presbyterian/Columbia University Irving Medical Center, who treats patients with long COVID in his clinic.
Over the past year, several large, well-conducted studies have borne out that theory, including the following studies:
- In the RECOVER study, published in May in the journal Nature Communications, researchers examined the electronic health records of more than 5 million people who had been diagnosed with COVID and found that vaccination reduced the risk that they would develop long COVID. Although the researchers didn’t compare the effects of having boosters to being fully vaccinated without them, experts have suggested that having a full round of recommended shots may offer the most protection. “My thoughts are that more shots are better, and other work has shown compelling evidence that the protective effect of vaccination on COVID-19 wanes over time,” said study coauthor Daniel Brannock, MS, a research scientist at RTI International in Research Triangle Park, N.C. “It stands to reason that the same is true for long COVID.”
- A review published in February in BMJ Medicine concluded that 10 studies showed a significant reduction in the incidence of long COVID among vaccinated patients. Even one dose of a vaccine was protective.
- A meta-analysis of six studies published last December in Antimicrobial Stewardship and Healthcare Epidemiology found that one or more doses of a COVID-19 vaccine were 29% effective in preventing symptoms of long COVID.
- In a June meta-analysis published in JAMA Internal Medicine, researchers analyzed more than 40 studies that included 860,000 patients and found that two doses of a COVID-19 vaccine reduced the risk of long COVID by almost half.
The message? COVID vaccination is very effective in reducing the risk of long COVID.
“It’s important to emphasize that many of the risk factors [for long COVID] cannot be changed, or at least cannot be changed easily, but vaccination is a decision that can be taken by everyone,” said Vassilios Vassiliou, MBBS, PhD, clinical professor of cardiac medicine at Norwich Medical School in England, who coauthored the article in JAMA Internal Medicine.
Why vaccines may be protective
The COVID-19 vaccines work well to prevent serious illness from the virus, noted Aaron Friedberg, MD, clinical coleader of the Post COVID Recovery Program at the Ohio State University Wexner Medical Center. That may be a clue to why the vaccines help prevent long COVID symptoms.
“When you get COVID and you’ve been vaccinated, the virus may still attach in your nose and respiratory tract, but it’s less likely to spread throughout your body,” he explained. “It’s like a forest fire – if the ground is wet or it starts to rain, it’s less likely to create a great blaze. As a result, your body is less likely to experience inflammation and damage that makes it more likely that you’ll develop long COVID.”
Dr. Friedberg stressed that even for patients who have had COVID, it’s important to get vaccinated – a message he consistently delivers to his own patients.
“There is some protection that comes from having COVID before, but for some people, that’s not enough,” he said. “It’s true that after infection, your body creates antibodies that help protect you against the virus. But I explain to patients that these may be like old Velcro: They barely grab on enough to stay on for the moment, but they don’t last long term. You’re much more likely to get a reliable immune response from the vaccine.”
In addition, a second or third bout of COVID could be the one that gives patients long COVID, Dr. Friedberg adds.
“I have a number of patients in my clinic who were fine after their first bout of COVID but experienced debilitating long COVID symptoms after they developed COVID again,” he said. “Why leave it to chance?”
Vaccines and ‘long vax’
The COVID vaccines are considered very safe but have been linked to very rare side effects, such as blood clots and heart inflammation. There have also been anecdotal reports of symptoms that resemble long COVID – a syndrome that has come to be known as “long Vax” – an extremely rare condition that may or may not be tied to vaccination.
“I have seen people in my clinic who developed symptoms suggestive of long COVID that linger for months – brain fog, fatigue, heart palpitations – soon after they got the COVID-19 vaccine,” said Dr. Purpura. But no published studies have suggested a link, he cautions.
A study called LISTEN is being organized at Yale in an effort to better understand postvaccine adverse events and a potential link to long COVID.
Talking to patients
Discussions of vaccination with patients, including those with COVID or long COVID, are often fraught and challenging, said Dr. Purpura.
“There’s a lot of fear that they will have a worsening of their symptoms,” he explained. The conversation he has with his patients mirrors the conversation all physicians should have with their patients about COVID-19 vaccination, even if they don’t have long COVID. He stresses the importance of highlighting the following components:
- Show compassion and empathy. “A lot of people have strongly held opinions – it’s worth it to try to find out why they feel the way that they do,” said Dr. Friedberg.
- Walk them through side effects. “Many people are afraid of the side effects of the vaccine, especially if they already have long COVID,” explained Dr. Purpura. Such patients can be asked how they felt after their last vaccination, such a shingles or flu shot. Then explain that the COVID-19 vaccine is not much different and that they may experience temporary side effects such as fatigue, headache, or a mild fever for 24-48 hours.
- Explain the benefits. Eighty-five percent of people say their health care provider is a trusted source of information on COVID-19 vaccines, according to the Kaiser Family Foundation. That trust is conducive to talks about the vaccine’s benefits, including its ability to protect against long COVID.