CDC changes COVID guidelines, recommends masks indoors in parts of country where virus surging

The policy change occurred as the virus' highly contagious delta variant increases case numbers, particularly among the unvaccinated.
New York City residents wearing masks

The Centers for Disease Control and Prevention on Tuesday revised its guidance on COVID-19 masking wearing, recommending even vaccinated people return to wearing one indoors in parts of the country where the virus is surging.

The agency also recommended indoor masks for all teachers, staff, students and visitors to schools, regardless of vaccination status, citing the ability of the virus' delta variant to spread among vaccinated people.

The new guidance follows recent decisions in Los Angeles and St. Louis to revert to indoor mask mandates amid a spike in COVID-19 cases and hospitalizations that have been especially bad in the South, according to the Associated Press.

The country is averaging over 57,000 cases a day and 24,000 COVID-19 hospitalizations, the wire service also reports. 

Most new infections in the U.S. are among unvaccinated people. But the so-called "breakthrough" infections, which generally cause milder illness, can occur in vaccinated people\