This map, generated by CDC data, shows that Cuyahoga County on Saturday reached "substantial" transmission of COVID-19, triggering the CDC recommendation that vaccinated people wear masks indoors.

CLEVELAND, Ohio – Cuyahoga County has reached the federal government’s threshold for “substantial” transmission of COVID-19, triggering the Centers for Disease Control and Prevention’s recommendation that vaccinated people return to wearing masks indoors.

Cuyahoga County appears to have hit the CDC’s benchmark over the weekend, moving from “moderate” transmission as of Friday, into “substantial” transmission as of Saturday, according to CDC data.

The CDC last week began recommending fully vaccinated people mask up indoors in areas with higher levels of transmission in response to a surge of COVID-19 cases across much of the U.S., fueled by the more-transmissible Delta variant.

With the recent designation of “substantial” transmission, Cuyahoga County is now among the 78.5% of counties nationwide in which the CDC is recommending vaccinated people mask up indoors.