CNN.com - RSS Channel - HP HeroWhat the CDC's 'substantial' and 'high' levels of Covid-19 transmission actually mean

Health guidance issued Tuesday recommends that fully vaccinated people wear masks indoors if they're in areas with "substantial" or "high" transmission of Covid-19. But what do "substantial" and "high" actually mean?

July 29, 2021 at 03:14AM https://ift.tt/3zZV9ED guidance issued Tuesday recommends that fully vaccinated people wear masks indoors if they're in areas with "substantial" or "high" transmission of Covid-19. But what do "substantial" and "high" actually mean?