Mask facts (COVID-19)
EDITOR: 1. Cloth masks are not very effective at preventing infection. In the first randomized clinical trial that included cloth masks, 1,607 health care workers were placed in three groups: Cloth masks, surgical masks, and “normal practice” which included some mask wear and some time without masks. Cloth masks wearers were 2.5 to 13 times more likely to get a clinical-respiratory-infection or influenza-like-infection than surgical mask wearers. The study was performed by faculty of the School of Public Health and Community Medicine, University of New South Wales, Sydney, ...