The Centers for Disease Control and Prevention reversed course Tuesday on some masking guidelines, recommending that even vaccinated people return to wearing masks indoors in parts of the U.S. where the coronavirus is surging.
Citing new information about the ability of the delta variant to spread among vaccinated people, the CDC also recommended indoor masks for all teachers, staff, students and visitors to schools, regardless of vaccination status.
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 across the nation, particularly in the South.
This comes two weeks after health officials in seven Bay Area counties made their own announcement, urging all residents, regardless of vaccination status, to again wear masks in public indoor spaces amid a recent sharp uptick in new COVID-19 cases fueled by the highly contagious delta variant.
The country is averaging more than 57,000 cases a day and 24,000 COVID-19 hospitalizations.
Most new infections in the U.S. continue to be among unvaccinated people. But “breakthrough” infections, which generally cause milder illness, can occur in vaccinated people. When earlier strains of the virus predominated, infected vaccinated people were found to have low levels of virus and were deemed unlikely to spread the virus much, CDC Director Dr. Rochelle Walensky said.
But with the delta variant, the level of virus in infected vaccinated people is “indistinguishable” from the level of virus in the noses and throats of unvaccinated people, Walensky said.
The data emerged over the last couple of days from 100 samples. It is unpublished, and the CDC has not released it. But “it is concerning enough that we feel like we have to act,” Walensky said.
Vaccinated people “have the potential to spread that virus to others,” she said.
For much of the pandemic, the CDC advised Americans to wear masks outdoors if they were within 6 feet of one another.