A team of medical professionals, clinicians, epidemiologists and political scientists recently published the results of a study that revealed new information about the prevalence of post-acute sequelae of SARS CoV-2 infection, otherwise known as “long COVID.”

Mauricio Santillana, professor physics and network science at Northeastern and director of the Machine Intelligence Group for the betterment of Health and the Environment, helped author the research that was published in the American Medical Association’s JAMA Network Open. The study includes data from eight waves of the COVID States Project, an online survey that spans all 50 states and was administered to more than 16,000 people every six weeks between Feb. 5, 2021, and July 6, 2022.

Santillana says the team is going to continue collecting data to refine its understanding of long COVID, defined in this study as “the persistence of COVID-19 symptoms beyond two months.” However, the study has already produced surprising insights into the prevalence of long COVID.

“What was interesting was we identified the degree to which women showed higher risk of developing long COVID,” Santillana says. “You’re almost twice as likely to get long COVID just being a woman, controlling for everything else.”

Santillana doesn’t currently have an explanation for why long COVID might be more prevalent among women, but he hopes the results of this study will provide new avenues for further research.

“It’s puzzling, and it’s an invitation for clinicians to start looking at whether there’s some mechanism that COVID may stay longer in the body for women,” Santillana says.

The study also found that older adults were more at risk, with the risk increasing every decade above age 40.

Santillana says his team’s data also indicates that each subsequent COVID-19 variant has led to less long COVID, although he acknowledges there is still not enough data to confirm definitively whether that will continue.

“I’m going to say that with caution because we are still monitoring the population, so we’ll see if that persists over time,” Santillana says.

Notably, the researchers found that the prevalence of long COVID among survey respondents, about 15% in U.S. adults, lined up well with similar studies in other countries.

“We’re seeing similar numbers, and it is substantial,” Santillana says. “If one in 10 or one in nine are getting long COVID, then it deserves attention.”

Researchers and medical professionals are still working to gain a better understanding of long COVID, and Santillana says every piece of information about post-COVID conditions is valuable. Symptoms can vary widely, from consistent, long-term fatigue to respiratory and heart issues, and can even be critical in some cases.

Santillana says the results of the study indicated vaccines also helped mitigate the risk of long COVID. Those who had received the first two doses of their COVID-19 vaccine had a 30% decrease in risk, and the scope of the published study did not yet include data with booster shots.

Santillana hopes to continue the study until next summer to continue learning more about long COVID and inform clinicians and public health officials about the impacts of COVID-19 beyond the initial infection.

“COVID will stay with us for years to come, so it will still be a thing,” Santillana says. “It will be great to characterize the risks associated with it and move forward so we can better document how to treat people and how we can learn to live with it in our societies.”

For media inquiries, please contact Marirose Sartoretto at m.sartoretto@northeastern.edu or 617-373-5718.