McKinnon, John E., Wang, Dee Dee, Zervos, Marcus, Saval, Matt, Marshall-Nightengale, Laurie, Kilgore, Paul, Pabla, Pardeep, Szandzik, Ed, Maksimowicz-McKinnon, Kathleen, and O'Neill, William W.
• Hydroxychloroquine chemoprophylaxis is safe in high-risk populations for COVID-19. • No increased cardiovascular risks were observed with hydroxychloroquine chemoprophylaxis. • Adverse events were similar between placebo and hydroxychloroquine treatment arms. Health care workers (HCW) are among the highest risk groups for acquisition of COVID-19 because of occupational exposures. The WHIP COVID-19 Study aimed to evaluate the safety and efficacy of hydroxychloroquine (HCQ) as chemoprophylaxis for SARS-CoV-2 infection in this population. HCW, first responders, and other occupationally high-risk participants were enrolled in a randomized, placebo-controlled clinical study of HCQ from April to October 2020. The trial compared daily versus weekly HCQ with placebo and with a prospective cohort on HCQ for autoimmune diseases. Participants were followed for 8 weeks. Serology or a positive polymerase chain reaction test was used to determine laboratory confirmed clinical cases. A total of 624 participants were randomized to placebo (n = 200), weekly HCQ (n = 201), daily HCQ (n = 197). For the primary safety end point, 279 (44.7%) participants experienced adverse event (AE) level II or lower (total AEs n = 589), similar rates in all randomized groups (P =.188) with no hospitalizations or interventions required. Only 4 laboratory confirmed COVID-19 cases occurred, with 2 in the placebo arm and one in each HCQ randomized arm. This randomized placebo-controlled trial was able to demonstrate the safety of HCQ outpatient chemoprophylaxis in high-risk groups against COVID-19. Future studies of chemoprophylaxis for SARS-CoV-2 are needed as the epidemic continues worldwide. [ABSTRACT FROM AUTHOR]