The Centers for Disease Control and Prevention said Tuesday that Americans fully vaccinated against the coronavirus should start wearing masks indoors again in parts of the country that are experiencing “substantial” or “high” transmission of the more infectious Delta variant.
“In rare occasions, some vaccinated people infected with the Delta variant after vaccination may be contagious and spread the virus to others,” CDC Director Rochelle Walensky said Tuesday during an afternoon press briefing. “This new science is worrisome and unfortunately warrants an update to our recommendations.”
The revised guidance on masks comes after top officials gathered Sunday night to review new data and evidence regarding the transmissibility of the Delta COVID-19 variant and a growing number of breakthrough cases, CNN reported. It reverses a recommendation from the agency in May that said fully vaccinated people would no longer need to wear masks in most indoor settings.
The CDC also recommended universal masking in K-12 schools, regardless of vaccination status, for teachers, students, and staff members.
Walensky said Tuesday that although existing COVID-19 shots authorized for use in the United States have proven formidable in largely protecting against severe cases of the Delta variant, her agency fears that the next iteration of COVID—“possibly a few mutations away”—could evade the vaccine.
When a particular county hits between 50 and 100 cases per 100,000 people over a seven-day period, transmission is considered substantial. More than 100 cases over the same period would move a county into the high transmission category.
Currently, large swaths of the country fall under these categories, with the exception of pockets in the Northeast and Midwest, CDC mapping shows.
In recent weeks, the agency resisted revising its recommendation from just two months ago that masks were largely no longer necessary for vaccinated people, even as the World Health Organization and others began encouraging mask use for immunized people as Delta ravaged several other countries.
The CDC’s revised recommendation is a sharp turn from just last week, when an agency spokesman clung to earlier guidance even as a growing number of doctors and experts criticized the health agency for letting up on masking too soon.
“At this time, we have no intention of changing our masking guidance,” CDC spokesperson Jason McDonald said in a statement on July 22.
The statement flew in the face of recommendations made by groups like National Nurses United and the American Academy of Pediatrics, who have encouraged masking in certain settings regardless of vaccination status.
As the agency put forward a strong public stance that it would remain firm on its guidance, public health experts have been cautioning that the pandemic has changed significantly since last May.
“This would have been my recommendation a month ago,” Irwin Redlener, a physician and founding director at the National Center for Disaster Preparedness at Columbia University told The Daily Beast.
“Guidelines should be written with the understanding that they are subject to change at a moment’s notice as we learn more about this disease,” he added.
On the same day the new mask guidance came out, CNN reported that President Joe Biden was preparing to announce a requirement for all federal employees and contractors to be vaccinated against COVID, with the exception of military personnel.
The move is meant to fight back against the now-dominant Delta variant by boosting the rate of vaccinations, which has plummeted in recent weeks.
At the time of Walensky’s spring mask guidance, over a million new people were getting vaccinated each day, and the CDC had hoped its announcement on masks at the time would spark vaccinations.
But in the wake of that announcement, vaccination rates have plateaued. Daily shots have lingered around 530,000 per day, after peaking at 3.38 million reported on April 13. Biden has yet to achieve his July 4 goal of getting 70 percent of adults at least partially vaccinated.
Walensky’s recommendation in May had also relied on scientific findings that showed few vaccinated people were getting infected and transmission rates were low. The updated guidance appears to acknowledge new data as scientists uncover the Delta’s variant’s role in breakthrough infections.
More than 88,000 new cases were reported across the U.S. on Monday. The number of new cases has quadrupled over the past month.
In addition, experts have cautioned that people infected with the Delta variant appear to carry a viral load that is dramatically higher than earlier versions of the virus and that causes it to spread more easily than its predecessors.
Lawrence Gostin, director of the World Health Organization’s collaborating center on global health law, told The Daily Beast that the public is “losing trust and confidence in the CDC,” amid ever-changing mask guidelines, which he said should be applied to all states.
“The CDC let the genie out of the bottle and people threw away their masks,” Gostin said. “It’s going to be hard to put the genie back in the bottle. Most people who are unvaccinated simply will not mask up. So, I think the damage has already been done.”
The agency is “partially responsible” for surges in states like Missouri, Arkansas, Louisiana, and Florida, where vaccination rates are lower, Gostin said.
“It was entirely foreseeable,” he added, particularly after similar surges have been tearing across European countries with higher vaccination rates for months.
“It’s truly maddening that it came this late,” Gostin said.