Women, adults with a history of cardiovascular disease, and people who are not vaccinated against SARS-CoV-2 are at heightened risk for developing long COVID, whose symptoms include fatigue, brain fog, and joint and muscle pain that persist for three months or longer after initial infection, according to a recent study by Columbia University researchers.
The study, which involved 4,700 Americans who had COVID-19 between 2020 and 2023, found that the average recovery time is twenty days and that about one in five people experience symptoms lasting longer than three months. It also found that people who catch Omicron variants, which have accounted for the vast majority of infections in the US since late 2021, are less likely to develop long COVID than those exposed to more virulent strains of SARS-CoV-2. People who are vaccinated recover more quickly from all strains.
“Our study underscores the important role that vaccination against COVID has played, not just in reducing the severity of an infection but also in reducing the risk of long COVID,” says Elizabeth C. Oelsner ’08VPS, ’24PH, a Columbia physician and epidemiologist who oversaw a team of nearly fifty medical and scientific experts who contributed to the new analysis.
A person’s chances of developing long COVID also appear to be slightly higher if they have other preexisting conditions — including diabetes, obesity, lung disease, or depression — or a history of smoking. But the associations found in the Columbia study between those factors and recovery time are quite weak and would require additional research to verify. “It’s possible that what we call long COVID is actually a number of related syndromes, each involving different risk factors like diabetes or lung disease, and that these factors will stand out more clearly if we examine specific subsets of patients,” says Oelsner.
Certain demographic groups, including American Indian and Alaska Native participants, were found to be disproportionately affected by long COVID, although the reasons for this are unclear.
Oelsner says that her team’s findings open up new avenues of research. “By identifying who is likely to experience a lengthy recovery, we have a better understanding of who should be involved in ongoing studies of how to lessen or prevent the long-term effects of SARS-CoV-2 infection.”
This article appears in the Fall 2024 print edition of Columbia Magazine with the title "Study reveals risk factors for long COVID."
