The use of masks by asymptomatic people to reduce COVID transmission

Abstract

This Evidence Snapshot found insufficient evidence that masks are effective in reducing transmission among asymptomatic people in community settings. There was a lack of high-level evidence, with small measures of effect found in some studies. However, 10 of the 13 peer reviewed studies held that face masks or coverings may reduce transmission of COVID-19. Six studies recommended facemasks in combination with handwashing and social distancing. Seven studies suggested that masks be worn: early in a pandemic (3 studies), where social distancing is relaxed (1 study), to prevent a second wave (1 study) or where social distancing is not feasible such as on public transport (2 studies). Agency position statements varied.