“Reinfection with COVID-19 increases the risk of both acute outcomes and long-term COVID-19,” said Dr. Ziyad Al-Aly of Washington University School of Medicine in St. Louis. “This was evident in unvaccinated, vaccinated and boosted people.” The findings come from US Department of Veterans Affairs (VA) data collected from March 1, 2020, to April 6, 2022, on 443,588 patients with one SARS-CoV-2 infection, 40,947 with two or more infections, and 5.3 million not infected persons. Most of the study subjects were men. Reinfected patients had more than twice the risk of death and more than threefold the risk of hospitalization compared to those who were infected by COVID only once. They also had increased risks for lung, heart, blood, kidney, diabetes, mental health, bone and muscle problems, and neurological disorders, according to a report published in Nature Medicine. “Even if someone had a previous infection and was vaccinated – meaning they had dual immunity from a previous infection plus vaccines – they are still susceptible to adverse outcomes after re-infection,” said Al-Aly, who led the study. People in the study with repeated infections were more than three times more likely to develop lung problems, three times more likely to suffer from heart disease and 60% more likely to develop neurological disorders than patients who were infected only once. The higher risks were most pronounced in the first month after reinfection, but were still evident six months later, the researchers found. Experts not involved in the study said the VA population does not reflect the general population. Patients at VA health facilities are generally older, sicker people and often men, a group that typically would have more than normal health complications, said John Moore, a professor of microbiology and immunology at Weill Cornell Medical College in New York. The researchers said the cumulative risks and burdens of re-infection increased with the number of infections, even after accounting for differences in COVID-19 variants such as Delta, Omicron and BA.5. But Dr. Celine Gounder, an infectious disease epidemiologist and editor-in-chief at Kaiser Health News, said there appears to be a “plateau effect with multiple infections,” with a smaller jump in risk after the second infection. “The good news there is that the better protected people are with immunity, the risk of developing some of the complications will likely be lower over time,” he added. However, Al-Aly warned that people should not let their guard down. “We were starting to see a lot of patients coming to the clinic with an air of invincibility,” he told Reuters. “They asked themselves, ‘Does recontamination really matter?’ The answer is yes, it absolutely does.” With the holiday season fast approaching with travel and indoor gatherings, “people should be aware that reinfection is consequential and should take precautions,” he added. Reporting by Nancy Lapid, additional reporting by Raghav Mahobe in Bangalore; Editing by Bill Berkrot
