Hydroxychloroquine does not offer COVID-19 protection after exposure according to University of Minnesota study.

A University of Minnesota trial with results published in the New England Journal of Medicine, goes the furthest in answering the question of whether a decades-old, repurposed hydroxychloroquine can help treat COVID-19, when considering early use after coronavirus exposure. Forty-nine of 414 people taking hydroxychloroquine and 58 of 407 people taking placebo developed symptoms consistent with COVID-19. One person in each group was hospitalized, and none died. Only 20 participants, 11 on hydroxychloroquine and nine on placebo, were confirmed to have COVID-19 through laboratory testing, due in part to the limited availability of viral tests during the study period. The others were all diagnosed symptomatically — a limitation that could mean some patients did not actually have coronavirus disease. "There was not a clinically meaningful benefit," said Caleb Skipper, an infectious disease postdoctoral fellow and an author on the NEJM paper, in an interview. The 2% difference observed between groups was "not beyond random chance." See- "A Randomized Trial of Hydroxychloroquine as Postexposure Prophylaxis for Covid-19"-David R. Boulware, M.D., M.P.H., Matthew F. Pullen, M.D.et al.,June 3, 2020 DOI: 10.1056/NEJMoa2016638.