During the COVID-19 pandemic, face masks, such as surgical masks and cloth masks, have been employed as a public and personal health control measure against the spread of SARS-CoV-2. In community and healthcare settings, their use is intended as source control to limit transmission of the virus and personal protection to prevent infection.
Population-wide masking has proven significant in reducing the transmission of COVID-19. Masks vary in efficacy, with N95 and surgical masks outperforming cloth masks, which are more common due to supply shortages, but even cloth masks, with their variability in fabric type and mask fit, protect wearers from COVID-19. Among readily available fabrics, double-layered cotton, hybrid masks, and cotton flannel perform best and filtration effectiveness generally improves with thread count. Healthcare workers, given their exposure, are recommended against using cloth masks. Small-scale observational studies have shown evidence that masks reduce the community spread of COVID-19. More reliable, randomized controlled population trials are uncommon due to ethical and logistical issues. Clinical studies had not evaluated the efficacy of cloth masks in COVID-19 transmission by the end of 2021.
The use of face masks (or coverings in some cases) has been recommended by American immunologist and NIAID director Anthony Fauci to reduce the risk of contagion.