The number of counties recommended to wear masks comes days after the CDC changed guidance to tell vaccinated individuals to wear masks indoors in areas with high or substantial transmission rates.

CDC data shows 52 percent of counties have high transmission of the virus, or more than 100 cases per 100,000 people in the past week.

A little more than 17 percent of counties have substantial transmission or more than 50 cases per 100,000 people in the past week.