Benefits of wearing masks in community settingswhere social distancing cannot be reliably achieved

Executive Summary

We review the evidence for the benefits of wearing face masks in community settings for diminishing the spread of SARS-CoV-2, particularly where social distancing and traceability cannot reliably be achieved. Compared to the early phases of the pandemic inSwitzerland (early March), the situation has evolved in three key aspects: (1) Additional scientific evidence has emerged supporting public use of face masks, both as an effective source control measure and for personal protection; (2) There is now broad scientific consensus that public use of face masks reduces the spread of SARS-CoV-2; and (3) Based on new evidence and the current scientific consensus, prominent health institutions including the WHO and the CDC have changed their recommendations with regard to face masks. In line with our earlier recommendation from April, we reiterate our recommendation in favor of generalized mask wearing in settings where physical distance cannot reliably and consistently be achieved, especially where traceability is not warranted, such as for example and with highest priority in public transport. In this policy brief we make the additional point that making mask-wearing mandatory in certain settings might be the right decision at this time.