Abstract
Background: Previously, we demonstrated that ivermectin use as prophylaxis for COVID-19 was associated with reductions in COVID-19 infection, hospitalization, and mortality rates, and in the risk of dying from COVID-19, irrespective of regularity and accumulated use of ivermectin, in an observational, prospectively obtained data from a strictly controlled city-wide program in a city in Southern Brazil (Itajaí, SC, Brazil) of medically-based, optional use of ivermectin as prophylaxis for COVID-19. In this study, our objective was to explore the data obtained from the program to evaluate whether the level of regularity of ivermectin use impacted in the reductions in these outcomes, aiming to determine if ivermectin showed a progressive dose- and regularity-response in terms of protection from COVID-19 and COVID-19 related outcomes. Materials and methods: This is a prospective observational study of the program mention above, that used ivermectin at a dose of 0.2mg/kg/day for two consecutive days, every 15 days.