To prevent further spread of the Delta variant, the US Centers for Disease Control and Prevention updated its mask guidance on Tuesday to recommend that fully vaccinated people wear masks indoors when in areas with "substantial" and "high" transmission of Covid-19, which includes nearly two-thirds of all US counties.
원문출처 : https://www.cnn.com/2021/07/27/health/cdc-mask-guidance-vaccinated-people-bn/index.html
원문출처 : https://www.cnn.com/2021/07/27/health/cdc-mask-guidance-vaccinated-people-bn/index.html