Healthcare Worker Exposure Response and Outcomes of Hydroxychloroquine Trial (HERO-HCQ Trial), United States, 2020-2021

Severe acute respiratory syndrome coronavirus 2 associated disease (COVID-19) is caused by a novel betacoronavirus, SARS-CoV-2, that was first isolated in January 2020 and has since caused a global pandemic unseen in decades in cases and mortality. At the time of initial protocol submission in April 2020, human vaccine clinical trials had just begun and experts predicted that a vaccine would not be available until April 2021 at the earliest. Therefore, new measures remained needed to prevent the spread of disease. In vitro studies suggested a potential moderate antiviral effect of hydroxychloroquine (HCQ).
This study aimed to evaluate the efficacy of HCQ to prevent COVID-19 clinical infection and to prevent viral shedding of SARS-CoV-2 among healthcare workers (HCWs), as well as to evaluate the safety and tolerability of HCQ. Participants prescreened through the Healthcare Exposure Response and Outcomes (HERO) Registry across 34 U.S. clinical centers were randomly assigned to take a placebo (n=676) or HCQ (n=683) for 30 days, with in-person clinic visits at baseline and 30 days, and an end-of-study virtual visit at 60 days. This collection contains analysis (DS1 through DS6) and tabulation (DS7 through DS44) data and accompanying documentation.