To get a handle on the health impact of reinfection, re-reinfection and even re-re-reinfection, three researchers—Ziyad Al-Aly from the Washington University School of Medicine plus Benjamin Bowe and Yan Xie, both from the V.A. St. Louis Health Care System—scrutinized the health records of 5.7 million American veterans.

Some 260,000 had caught COVID just once, and 40,000 had been reinfected at least one more time. The control group included 5.4 million people who never got COVID at all. Al-Aly, Bowe and Xie tracked health outcomes over a six-month period and came to a startling conclusion. “We show that, compared to people with first infection, reinfection contributes additional risks,” they wrote in their study, which hasn’t been peer-reviewed yet but is under consideration for publication in Nature.

Every time you catch COVID, your chance of getting really sick with something—likely COVID-related—seems to go up, Al-Aly, Bowe and Xie found. The risk of cardiovascular disorders, problems with blood-clotting, diabetes, fatigue, gastrointestinal and kidney disorders, mental health problems, musculoskeletal disorders and neurologic damage all increase with reinfection—this despite the antibodies that should result from repeat infections.