NEW - Peer-reviewed, large PSM study from Brazil finds, "regular use of ivermectin as a prophylactic agent was associated with significantly reduced COVID-19 infection, hospitalization, and mortality rates." 

The study was published in the Cureus Journal of Medical Science today:

https://www.cureus.com/articles/82162-ivermectin-prophylaxis-used-for-covid-19-a-citywide-prospective-observational-study-of-223128-subjects-using-propensity-score-matching