Hydroxychloroquine is no more effective than a vitamin placebo in preventing COVID-19 in individuals who have been exposed to the disease, according to a study released June 3 from the Minneapolis-based University of Minnesota Medical School.
The study, which began in mid-March, is the first to test the malaria drug as a preventative measure. Researchers enrolled 800 people in the U.S. and Canada, most of which were front-line healthcare workers, who had been exposed to someone with COVID-19.
Participants received either hydroxychloroquine or a vitamin placebo for five days and were then monitored for two weeks. The study was double-blinded, so neither the participants nor the researchers knew which medication was being received.