July 29, 2021: -On Tuesday, the Centers for Disease Control and Prevention recommended that fully vaccinated people begin wearing mask indoors again in places with high Covid-19 transmission rates. The agency is also recommending kids wear masks in schools this fall.

Federal health officials still believe fully vaccinated individuals represent a minimal amount of transmission. Still, some vaccinated people could be carrying higher levels of the virus than previously understood and potentially transmit it to others.

“This pandemic continues to pose a serious threat to the health of all Americans,” CDC Director Rochelle Walensky told reporters on a call. “Today, we have new science related to the delta variant that requires us to update the guidance regarding what you can do when you are fully vaccinated.”

The updated guidance comes ahead of the fall season when the highly contagious delta variant is expected to cause another surge in new coronavirus cases. Many large employers plan to bring workers back to the office. In mid-May, the CDC said fully vaccinated people didn’t need to wear masks in most settings, whether indoors or outdoors.

“In areas with substantial and high transmission, CDC recommends fully vaccinated people wear masks in public, indoor settings to help prevent the spread of the delta variant, and protect others. This includes schools,” Walensky said. The CDC recommends that everyone in grade schools wear masks indoors, “which include teachers, staff, students, and visitors, regardless of vaccination status.”

Walensky said new data shows the variant behaves “uniquely differently from past strains of the virus,” indicating that some vaccinated people infected with the delta variant “may be contagious and spread the virus to others.”

White House chief medical advisor Dr. Anthony Fauci said Sunday that the CDC was considering whether to revise mask guidance for vaccinated Americans, saying it was “under active consideration.”

“It’s a dynamic situation. It’s a work in progress, and it evolves like in so many other areas of the pandemic,” Fauci, also the director of the National Institute of Allergy and Infectious Diseases, told CNN. “You’ve got to look at the data.”

The CDC’s guidance is only a recommendation, leaving it up to states and local officials to reintroduce their mask rules for certain people. But even before the CDC’s anticipated guidance Tuesday, some regions were reintroducing mask mandates and advisories as Covid cases began to spike again.

President Joe Biden said the CDC’s updated guidance was necessary to defeat the virus and that he will lay out “next steps” to get more Americans vaccinated on Thursday.

“Although most U.S. adults are vaccinated, too many are not. While we have seen an increase in vaccinations in recent days, we still need to do better,” he said.