Masks are being recommended for vaccinated people for use indoors in areas with substantial and high COVID transmission, said Centers for Disease Control Director Rochelle Walensky, in a Tuesday news conference. The CDC updates its mask guidance to compensate for the threat of the Delta variant.

Only 39 of Indiana’s 92 counties remained at the lowest threat level, according to the state’s dashboard on the Department of Health website. Four counties were in the orange. That differs from CDC data, which shows some of the same counties which are low transmission on the state map, as moderate on the CDC map.

“We continue to strongly encourage everyone to get vaccinated, said Walnesky, before announcing the new recommendations.

Though the guidance included people in substantial or high transmission areas, Walensky said everyone in schools should wear a mask, regardless of vaccination status.

“CDC recommends localities encourage universal indoor masking for all teachers, staff, students, and visitors to schools, regardless of vaccination status,” said the CDC, in a summary of the new guidance. “Children should return to full-time, in-person learning in the fall, with proper prevention strategies in place,” said Walensky.

She said the Delta variant has shown itself to be highly transmissible, but that vaccinations are still the best way to cut down on its transmission and affectivity.

“We continue to estimate that the risk of a breakthrough infection with symptoms upon exposure to the Delta variant is reduced by seven fold. The reduction is 20 fold for hospitalizations and death,” she said.