COVID-19 Breakthrough Infection after Vaccination and Substance Use Disorders: A Longitudinal Cohort of People with and Without HIV Receiving Care in the United States Veterans Health Administration

Research regarding HIV, substance use disorders (SUD), and SARS-CoV-2 infections after COVID-19 vaccination is limited. In the Veterans Aging Cohort Study (VACS)–HIV cohort, we followed vaccinated persons with HIV (PWH) and without HIV (PWoH) from 12/2020 to 3/2022 and linked SARS-CoV-2 test results for laboratory-confirmed breakthrough infection through 9/2022. We examined associations of substance use (alcohol use disorder [AUD], other SUD, smoking status) and HIV status and severity with breakthrough infections, using Cox proportional hazards regression hazard ratios (HR). To test for potential interactions between substance use and HIV, we fit survival models with a multiplicative interaction term. Among 24,253 PWH and 53,661 PWoH, 8.0