Mask Use and #Ventilation Improvements to Reduce #COVID-19 Incidence in Elementary Schools — Georgia, November 16–December 11, 2020 | MMWR
▻https://www.cdc.gov/mmwr/volumes/70/wr/mm7021e1.htm
COVID-19 incidence was 37% lower in schools that required teachers and staff members to use masks and 39% lower in schools that improved ventilation. Ventilation strategies associated with lower school incidence included dilution methods alone (35% lower incidence) or in combination with #filtration methods (48% lower incidence).
Par contre...
▻https://twitter.com/zeynep/status/1395764679918641152
“And once again, unlike the benefits associated with mitigations based on #aerosol dominance, masks and ventilation, the two costly mitigations in schools based on theories of droplet prominence, barriers and desk-spacing, were not associated with a real reduction of COVID risk.”
