Face masks during the COVID-19 pandemic

During the COVID-19 pandemic, face masks or coverings, including N95, FFP2, surgical, and cloth masks, were used as public and personal health control measures against the spread of SARS-CoV-2, the virus that causes COVID-19.

In community and healthcare settings, the use of face masks was intended as source control to limit transmission of the virus and for personal protection to prevent infection. When properly worn, face masks can limit the respiratory droplets and aerosols that are spread by infected individuals, helping protect healthy individuals from infection.

Scientific studies have concluded that the use of face masks is effective in protecting the individual using them against COVID-19. Various case-control and population-based studies have also shown that the increased use of masks in a community reduces the spread of SARS-CoV-2, although there is a paucity of evidence from randomized controlled trials (RCTs). Masks vary in their effectiveness. Fitted N95s outperform surgical masks, while cloth masks provide marginal protection. During the public health emergency, governments widely recommended (and, in some jurisdictions, mandated) the wearing of masks. Prominent national and intergovernmental health agencies and their leaders recommended the use of masks to reduce transmission, including the WHO, American, European, and Chinese Centers for Disease Control and Prevention.