Many people have contracted COVID-19 more than once thanks to the highly contagious Omicron variant. For those who were lucky enough not to experience new or lingering symptoms the first time around, the question arises: what’s the likelihood of developing Long COVID after a second infection? NPR science correspondent Rob Stein reports on research from the U.S. and U.K. that may provide some peace of mind.*

U.S. research on Long COVID risk after reinfection

A large 2022 study by the U.S. Veterans Administration (VA) examined whether reinfection with SARS-CoV-2 virus would compound the risk of Long COVID after initial infection. Investigators looked at patient data from:

• 443,588 people with one COVID infection,
• 40,947 people with two or more infections, and
• 5,334,729 non-infected controls.

The researchers found that after one year, the risk of Long COVID decreased from roughly 10% after initial infection to roughly 6% after a second infection.

Washington University epidemiologist Ziyad Al-Aly, M.D., FASN, who directed the study, said the results show “very, very clearly” that Long COVID risk is lower after the second infection than the first.

In a separate and ongoing study, statistician Daniel Ayoubkhani from the Office for National Statistics looked at Long COVID risk reduction in the U.K.

What the researchers did

For the U.K. study, over a half-million U.K. residents were analyzed over four weeks, using U.K. Coronavirus Infection Survey Data. The information in this report is up to date as of March 5, 2023.

Participants were monitored for Long COVID symptoms, of which fatigue and difficulty concentrating were the most prevalent.

What they found

Ayoubkhani’s findings have so far been consistent with the VA’s research.

• 4% of participants reported Long COVID symptoms lasting at least a month from their first infection.
• Conversely, only 2.4% of those who didn’t have Long COVID after initial infection reported lingering symptoms after their second infection.

“That’s a significant reduction in the odds,” said Ayoubkhani. “It does seem that the risk is significantly lower the second time around than the first time around for developing long COVID.”

What it means

Ayoubkhani is quick to point out that this doesn’t mean the risk of Long COVID is insignificant. “It’s not impossible to develop Long COVID the second time if you didn’t develop it the first time. I think that’s the key takeaway from our study.”

Why Long COVID risk decreases after a second infection is unclear. According to Ayoubkhani, it may have to do with:

• Increased immunity from the first infection
• Less susceptibility
• Infection with milder disease-causing virus strains, like Omicron
• Improved acute COVID-19 treatments

The study didn’t look at Long COVID risk after three or four infections, nor did it investigate whether a second infection makes existing Long COVID worse.

Hopeful for the future

Al-Aly notes that, while Long COVID risk is lower for any individual after a second infection, “that risk is not zero.” There is still a growing number of cases on a population level, since many people are still contracting COVID-19.

He believes, however, that Long COVID risk will continue to go down after each ensuing infection, and says he’s hopeful that reinfection will eventually add “trivial” or “non-consequential” risks.

*Stein, R. (2023, April 14). You’re less likely to get long COVID after a second infection than a first. NPR. https://www.npr.org/sections/health-shots/2023/04/14/1169216517/youre-less-likely-to-get-long-covid-after-a-second-infection-than-a-first