Outcomes of SARS-CoV-2 Reinfection

Abstract First infection with SARS-CoV-2 is associated with increased risk of acute and post-acute death and sequelae in the pulmonary and extrapulmonary organ systems. However, whether reinfection adds to the risk incurred after the first infection is not clear. Here we use the national health care databases of the US Department of Veterans Affairs to build a cohort of people with first infection (n = 257,427), reinfection (2 or more infections, n = 38,926), and a non-infected control group (n = 5,396,855) to estimate risks and 6-month burdens of all-cause mortality, hospitalization, and a set of pre-specified incident outcomes. We show that compared to people with first infection, reinfection contributes additional risks of all-cause mortality, hospitalization, and adverse health outcomes in the pulmonary and several extrapulmonary organ systems (cardiovascular disorders, coagulation and hematologic disorders, diabetes, fatigue, gastrointestinal disorders, kidney disorders, mental health disorders, musculoskeletal disorders, and neurologic disorders); the risks were evident in those who were unvaccinated, had 1 shot, or 2 or more shots prior to the second infection; the risks were most pronounced in the acute phase, but persisted in the post-acute phase of reinfection, and most were still evident at 6 months after reinfection. Compared to non-infected controls, assessment of the cumulative risks of repeated infection showed that the risk and burden increased in a graded fashion according to the number of infections. The constellation of findings show that reinfection adds non-trivial risks of all-cause mortality, hospitalization, and adverse health outcomes in the acute and post-acute phase of the reinfection. Reducing overall burden of death and disease due to SARS-CoV-2 will require strategies for reinfection prevention.