The potential risks of COVID reinfection are very real, regardless of your vaccination status, new research suggests. Having COVID more than once boosts your risk of hospitalization, developing long COVID, or even dying from the virus, according to a large new study published in the journal Nature Medicine.
The goal of the research was to determine whether the risk of complications goes up the more you’re infected with the virus, according to lead study author Ziyad Al-Aly, MD, assistant professor at the School of Medicine at Washington University in St. Louis. “The answer is absolutely yes,” he tells SELF.
For the study, Dr. Al-Aly’s team used data from the US Department of Veterans Affairs (VA). The researchers included 519,767 people who were initially infected and tested positive for COVID between March 1, 2020, and April 6, 2022. Of those people, 40,947 were reinfected between June 1, 2020, and June 25, 2022. The infected and reinfected groups were compared to a control group of more than 5.3 million people.
What they concluded is harrowing: People who are infected with COVID two or more times are twice as likely to die for any reason; three times as likely to need hospitalization; three times as likely to have lung problems; three times as likely to have cardiovascular problems; and three times as likely to have a blood clot. They’re also more likely to experience fatigue, gastrointestinal disorders, kidney disorders, mental health disorders, diabetes, musculoskeletal disorders, and neurological disorders. The risk of developing complications from COVID is likely highest during the first 30 days of the infection, Dr. Al-Aly says.
It could be that some people’s risk of these complications is higher than others, but Dr. Al-Aly’s team didn’t do subgroup analyses, he says—meaning, experts don’t yet know if these health issues are more or less of a threat to certain people after reinfection. Regardless, the study underscores that everyone should be especially cautious of long COVID symptoms after testing positive for the virus, especially after a reinfection, Thomas Russo, MD, an infectious disease expert at the University of Buffalo Jacobs School of Medicine and Biomedical Sciences, tells SELF.
While more research needs to be done, the study helps solidify what doctors and scientists have been trying to communicate for years now, Dr. Al-Aly says: “COVID is absolutely not a common cold, not even a flu. This is far more serious than that,” he explains. “If you had it before, you’re not sealed from adverse events.”
Though the study included a large number of people, it’s worth mentioning that the participant pool may not reflect the diversity in the US (or the world), Dr. Russo says, since people in the VA database are more likely to be cis men and have underlying health problems. Only about 10% of study participants were women, and they weren’t divided into subgroups by age, race, or sex assigned at birth. The study authors also acknowledged that the way we think about reinfections will likely change as more research on the topic is explored.