Respiratory virus shedding in exhaled breath and efficacy of face masks

We identified seasonal human coronaviruses, influenza viruses and
rhinoviruses in the exhaled breath and coughs of children and adults with
acute respiratory illness. Surgical face masks significantly reduced
detection of influenza virus RNA in respiratory droplets and coronavirus
RNA in aerosols, with a marginally significant reduction in coronavirus
RNA in respiratory droplets. Our results indicate that surgical facemasks
could prevent transmission of human coronaviruses and influenza viruses
from symptomatic individuals.