Severe Acute Respiratory Syndrome Coronavirus 2 Reinfection Cases Corroborated by Sequencing.

Evaluating cases of reinfection may offer some insight into areas for further investigation regarding durability of immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Sixty cases of reinfection with viral sequencing were identified in PubMed, Embase, Web of Science, and medRxiv before May 1, 2021.Episodes of infection were separated by a median of 116 days. Severity of illness was greater among individuals reinfected within 90 days of initial infection, no asymptomatic initial cases developed severe reinfection, nearly half of cases had suspected escape variants, and nearly all individuals tested following reinfection were found to have detectable levels of anti-SARS-CoV-2 antibodies. This analysis is limited by the heterogeneous methods used among reports. Reinfection continues to be relatively rare. As the case rate presumably increases over time, this review will inform measurements to determine the natural history and causal determinants of reinfection in more rigorous observational cohort studies and other standardized surveillance approaches.