Severe Acute Respiratory Syndrome Coronavirus 2 Reinfection Associates With Unstable Housing and Occurs in the Presence of Antibodies

Background The factors associated with severe acute respiratory coronavirus 2 (SARS-CoV-2) reinfection remain poorly defined. Methods We identified patients with SARS-CoV-2 infection and at least 1 repeat reverse transcription polymerase chain reaction result a minimum of 90 days after the initial positive test and before 21 January 2021. Those with a repeat positive test were deemed to have reinfection (n = 75), and those with only negative tests were classified as convalescents (n = 1594). Demographics, coronavirus disease 2019 (COVID-19) severity, and treatment histories were obtained from the Boston Medical Center electronic medical record. Humoral responses were analyzed using SARS-CoV-2-specific enzyme-linked immunosorbent assays and pseudovirus neutralizations in a subset of reinfection (n = 16) and convalescent samples (n = 32). Univariate, multivariate, and time to event analyses were used to identify associations. Results Individuals with reinfection had more frequent testing at shorter intervals compared with the convalescents. Unstable housing was associated with more than 2-fold greater chance of reinfection. Preexisting comorbidities and COVID-19 severity after the initial infection were not associated with reinfection. SARS-CoV-2 immunoglobulin G levels and pseudovirus neutralization were not different within the early weeks after primary infection and at a timepoint at least 90 days later in the 2 groups. In the convalescents, but not in those with reinfection, the late as compared with early humoral responses were significantly higher. Conclusions Reinfection associates with unstable housing, which is likely a marker for virus exposure, and reinfection occurs in the presence of SARS-CoV-2 antibodies. SARS-CoV-2 reinfection occurred at greater frequency among individuals with housing instability, and it did not associate with preexisting comorbidities or COVID-19 severity after first infection. Antibodies were detectable among the subset of individuals with documented reinfection examined in this study.