Long-term benefit of wearing masks for endemic diseases depend on the biology of transmission and immunity

Masking—along with social distancing, hand washing, and other so-called “non-pharmaceutical interventions” (NPIs)—proved very effective at limiting the spread of COVID-19, and simultaneously drove down rates of endemic diseases like colds, flu, RSV and others. This prompted infectious disease researchers to ask whether longer-term implementation could reduce flu and RSV outbreak over the long term.