Healthcare Worker Exposure Response and Outcomes of Hydroxychloroquine

This is a double blind, placebo controlled study in approximately 2,000 health care workers at risk for being exposed to COVID-19. Eligible participants will be randomly assigned (1:1) to either treatment group (HCQ) or placebo in a double-blind fashion. After enrollment, baseline assessments will include nasopharyngeal swab for COVID-19 and a blood sample to detect seroconversion to COVID-19. For convenience, follow-up will be performed weekly through a direct to participant portal. A call center will provide support for any missed visits. Follow-up includes screening for any COVID-19 clinical infections, other respiratory infections, clinical events, adverse events, and Quality of Life (QoL) assessments. Course of treatment is 30 days. Participants are followed via survey weekly. At the end of treatment participants will return for repeat nasopharyngeal swab for COVID-19 and a blood sample to detect seroconversion to COVID-19. There will be one last contact at 8 weeks (2 months) from baseline.