The coronavirus disease 2019 (Covid-19) pandemic has uniquely affected prisons and jails across the country. The incidence of Covid-19 among incarcerated persons is nearly six times that among nonincarcerated community members.1 The Centers for Disease Control and Prevention, the National Academy of Medicine, and the American Medical Association have recommended prioritization of prison and jail populations for deployment of Covid-19 vaccines, but vaccine rollout has varied across these settings,2 and few studies have been conducted on the effectiveness of vaccination efforts in congregate housing. Most of such studies have been performed in skilled nursing facilities, where vaccine effectiveness has been measured at 63 to 64%
