(NATURE) – In a recent article published by Nancy Leung, et al in Nature Medicine in April 2020, results indicate that masks do have efficicacy in prevention of transmission, adding to the literature showing mixed results. Here is another article that does demonstrate masks are beneficial.

Per Dr. Leung and her colleagues “We identified seasonal human coronaviruses, influenza viruses and rhinoviruses in exhaled breath and coughs of children and adults with acute respiratory illness. Surgical face masks significantly reduced detection of influenza virus RNA in respiratory droplets and coronavirus RNA in aerosols, with a trend toward reduced detection of coronavirus RNA in respiratory droplets. Our results indicate that surgical face masks could prevent transmission of human coronaviruses and influenza viruses from symptomatic individuals.”