(Washington, DC) — The CDC is updating its mask guidance, recommending that vaccinated people wear masks indoors in areas where there are high levels of infection. On a media call, CDC Director Rochelle Walensky said this will help prevent the spread of the highly transmissible Delta variant. She said the vast majority of transmission is being spread among unvaccinated individuals, but there are some breakthrough cases. Walensky said, “vaccinating more Americans now is more urgent than ever.”

The CDC is also recommending that all students in kindergarten through 12th grade should wear masks when they return to schools this fall, including students who have been vaccinated. Walensky said students can return in-person with the proper prevention strategies.