Hydroxychloroquine is not effective in preventing the development of COVID-19 in people exposed to the novel coronavirus, a new study involving Canadian researchers concludes. The results are published today in the New England Journal of Medicine. The clinical trial was led in Canada by Dr. Todd Lee and Dr. Emily McDonald of the Research Institute of the McGill University Health Centre, in conjunction with partners at the University of Manitoba and University of Alberta. The Canadian research is co-ordinated with a large study by Dr. David Boulware at the University of Minnesota. It is the first double-blind, randomized, placebo-controlled trial to be completed assessing the effectiveness of the malaria drug hydroxychloroquine in preventing COVID-19.