Early in the pandemic, many people infected with SARS-CoV-2 or COVID-19 reported persistent symptoms for a month or more, much longer than typical for an upper respiratory viral infection, or developed new, lingering symptoms even after recovery.

Although the exact causes of post-COVID-19 conditions or “long COVID” are still unclear, a recent study by researchers at Columbia University Vagelos College of Physicians and Surgeons confirmed the significant impact of long COVID and identified those most at risk.

The study, published in JAMA Network Open, shows that individuals with mild infections, including those vaccinated against SARS-CoV-2 and those infected with the Omicron variant, recover more quickly.

Recovery times were similar for subsequent infections.

“Our study highlights the important role of COVID vaccination, not only in reducing the severity of infection but also in reducing the risk of long COVID,” said Elizabeth C. Oelsner, MD, lead author of the study and the Herbert Irving Associate Professor of Medicine.

More information about the study

The research included more than 4,700 participants from the Collaborative for COVID-19 Research (C4R) who reported their time to recovery following SARS-CoV-2 infection.

From 2020 to early 2023, the average time to recovery following infection was 20 days, with one in five adults not recovering within three months.

Women and adults with heart disease before the pandemic were less likely to recover within three months.

Other pre-pandemic health conditions, such as chronic kidney disease, diabetes, asthma, chronic lung disease, depressive symptoms and a history of smoking, were initially associated with longer recovery times.

However, these associations became insignificant after considering gender, heart disease, vaccinations, and variant exposure.

“Despite suggestions that patients with long Covid often face mental health challenges, our study found that depressive symptoms prior to infection were not a major risk factor for long Covid,” Oelsner said.

In addition, American Indian and Alaska Native participants were disproportionately affected by long Covid, experiencing more severe infections and taking longer to recover.

“Our study clearly demonstrates that long COVID is a significant individual and societal burden,” said Oelsner. “By identifying people most likely to have a long-term recovery, we can better target ongoing studies aimed at reducing or preventing the long-term effects of SARS-CoV-2 infection.”