The Centers for Disease Control and Prevention (CDC) on Tuesday essentially reversed earlier COVID-19 guidance by saying fully vaccinated people should now wear masks in certain situations.
The agency said fully vaccinated people should wear masks in "public, indoor settings" in areas of the country with "substantial" or "high" levels of transmission, as defined by the CDC. Those areas currently include much of the South and West.
The CDC also said all adults and students should wear masks in K-12 schools regardless of vaccination status.
The new guidance contrasts with coronavirus recommendations from May, when the CDC said fully vaccinated people did not need to wear masks, except in a few circumstances.
CDC Director Rochelle Walensky on Tuesday said the change was needed because of new science showing that with the delta variant, some vaccinated people could transmit the virus to others on "rare occasions."
"This new science is worrisome and unfortunately warrants an update to our recommendations," Walensky said.
The CDC is still urging unvaccinated people to get the shot, saying it continues to overwhelmingly protect against severe outcomes of the disease, even with the delta variant.
In areas of the country with lower transmission rates, vaccinated people can continue without masks indoors, the CDC said. Those areas include New England and much of the Midwest, where the chances of vaccinated people getting infected are much lower.
For places with higher transmission, it will still be up to local governments to decide whether to impose mask mandates. Many of those areas are in GOP-led parts of the country that are unlikely to require masks.
President BidenJoe BidenHouse Democrat threatens to vote against party's spending bill if HBCUs don't get more federal aid Overnight Defense & National Security — The Pentagon's deadly mistake Haitians stuck in Texas extend Biden's immigration woes MORE urged people to follow the new guidance.
"Today’s announcement by the CDC—that new research and concerns about the Delta variant leads CDC to recommend a return to masking in parts of the country—is another step on our journey to defeating this virus," he said. "I hope all Americans who live in the areas covered by the CDC guidance will follow it; I certainly will when I travel to these areas."
He also called for schools to reopen full time.
"Today, the CDC also reaffirmed that we can safely reopen schools this fall—full time," Biden said. "Masking students is inconvenient, I know, but will allow them to learn and be with their classmates with the best available protection."
The change for high transmission areas was made because of the risk vaccinated people could pose to others, including children under 12, who cannot yet be vaccinated, and immunocompromised people, who do not get the same protections from vaccines, Walensky said.
The new data showed that with the delta variant, vaccinated people in some cases could carry the same amount of virus, known as the "viral load," as unvaccinated people, posing a transmission risk.
"This was not a decision that was taken lightly," Walensky said, adding that it had weighed on her and she knows people are "tired" and "frustrated" after months of the pandemic.
But Walensky said that when she showed other experts data on the potential for vaccinated people to transmit the virus, they agreed a change was needed.
The White House has trumpeted the progress against the virus, but officials emphasized that they would follow the recommendations from experts at the CDC.
White House press secretary Jen PsakiJen PsakiOvernight Health Care — FDA panel backs boosters for some, but not all White House to host global COVID-19 summit next week Overnight Defense & National Security: US-Australian sub deal causes rift with France MORE said Biden was briefed earlier Tuesday by Anthony FauciAnthony FauciWatch live: White House COVID-19 response team holds briefing Intercept reporters discuss gain-of-function research The Hill's 12:30 Report - Presented by Facebook - DC prepares for Saturday of festivals & Jan. 6 demonstration MORE, his top medical adviser.
The CDC guidance was praised by many health experts.
"Glad the CDC is finally doing what many of us in public health have been urging," tweeted Leana Wen, an emergency physician and public health professor at George Washington University. "The reality on the ground has changed, and the Biden administration is acknowledging that their guidance has to change accordingly."
But some Republicans blasted the move.
“The CDC’s updated guidance deeply undermines vaccine confidence," said Rep. Cathy McMorris RodgersCathy McMorris RodgersBiden administration rolls out clean car goals Biden, Pelosi struggle with end of eviction ban Latina lawmakers discuss efforts to increase representation MORE (R-Wash.). "Mask mandates for more command and control will not build trust — only resentment."
She noted that children are at lower risk from the virus and warned of "the harms of masks to our kids’ mental health and their emotional and social development."
Updated: 3:55 p.m.