correction

An earlier version of this article incorrectly included Georgia in a list of states barring school districts from imposing mask mandates. Also, in Texas the move was by executive order, not legislation. The article has been corrected.

The Centers for Disease Control and Prevention on Tuesday changed its guidance for schools, recommending everyone over the age of 2 — and not just the unvaccinated — wear masks inside school buildings, a shift that comes in response to rising concerns about the delta variant of the coronavirus.

The announcement came as schools across the country weighed how to mitigate the spread of the new variant in classrooms and hallways, a question that has been fiercely debated in school board meetings — where some parents have flung obscenities at school leaders — and statehouses. In many places, politics — not science — is guiding how leaders respond. And the guidance might make little difference for schools in the nine Republican-led states that have outright barred them from enacting mask requirements.

CDC Director Rochelle Walensky said in a news conference Tuesday that the agency decided to change the school guidance because of rising coronavirus rates, and because less than a third of 12-to-17-year-olds have been vaccinated. Previously, the agency said only unvaccinated people needed to wear masks indoors, which would have allowed vaccinated staff members and older students to go without them.

The new recommendations say children do not need to mask when they head outdoors for recess or physical education, for example, unless they will be standing in a crowd for long periods of time. That also puts the health agency in line with the American Academy of Pediatrics, which last week recommended that everyone over the age of 2 wear masks in school.

Top health officials Anthony S. Fauci and Rochelle Walensky said July 28 that vaccinated individuals should wear masks indoors, per new CDC guidance. (The Washington Post)

Wearing masks has been cited by health experts as one of the most effective health measures to stop the spread of the coronavirus. In late June, a report by two Duke University scientists who reviewed data from March through June 2021 in 100 school districts and 14 charter schools in North Carolina found that wearing masks effectively prevented the transmission of the virus in schools and on buses even without physical distancing.

Nonetheless, mask requirement proposals have stirred ugly fights in some school districts, just as they have spawned altercations in stores and restaurants. Many Republican leaders have opposed mask mandates because they reject the science that shows it can slow the spread of the coronavirus. Instead, they say, it should be left up to individuals to decide whether to protect themselves.

While many districts say they are still evaluating data about coronavirus rates in their areas before setting masking policies, at least nine states — all led by Republicans, including Arkansas, Arizona and Texas — have barred school districts from imposing mask mandates. And some districts had already decided that some or all students would wear masks. Some policies require masks be worn by everybody in elementary school buildings but only the unvaccinated in middle and high schools, while others just encourage all older students to wear them.

Paul Imhoff, superintendent of the Upper Arlington Schools district in Ohio and president of the AASA, the School Superintendents Association, lamented that the debate over how to control the coronavirus had become fraught with politics, complicating even the most straightforward measures, such as mask requirements.

“A mask mandate sounds easy, but on the ground how do you actually enforce that? These are questions we are left to grapple with, school district to school district to school district,” Imhoff said. “It’s very political. What we want to do is educate kids. We want to focus on learning loss, the well-being of kids and the things they went through during the pandemic. Instead, we are being forced to focus on this.”

In many places, where state leaders already eschew advice from the CDC, the change in guidance is unlikely to make a difference. Misty Belford, chair of the school board in Brevard County, Fla., said the debate over masks has raged for months. In April, the state’s education commissioner said schools would not be allowed to require masks. And the state’s governor, Ron DeSantis (R), said he would resist any effort to mandate them, falsely claiming that the CDC’s masking requirements were not based in science.

“At this point, I feel like my hands are tied at the direction of the state,” Belford said.

Even so, she said the change in guidance is unlikely to make a difference in the anti-mask crowd, where people are already deeply skeptical of the CDC. At one meeting, she recalled, “We had one lady who wore a Pinocchio nose and claimed that everything that came out of the CDC and Dr. Fauci were lies.”

“I feel like people have kind of drawn a line in the sand,” she added.

The change in guidance did prompt some districts to tighten their restrictions. On Tuesday, the school districts that encompass Las Vegas and New Orleans both announced they would require masks for everyone. Several other large urban districts, including those in New York City, Los Angeles and Chicago, already had universal masking requirements.

Some students have protested the wearing of masks, including some in Hamburg, N.Y., and at school board meetings in some Illinois districts. But Dan Domenech, executive director of AASA, said that students largely did not have problems wearing masks during the last school year and that it makes no sense for children and adults to go maskless in schools with the delta variant spreading fast.

In schools with no masking requirements, students and staff will still be free to wear them if they wish. But without the requirement, students might be unwilling to wear them if all of their classmates have forgone them.

Shivi Mehta, 14, a rising freshman at Alliance Academy in Forsyth County, Ga., said she started wearing a mask at school as soon as she returned for in-person learning, even though there has never been a requirement, and even as unmasked classmates urged her to take it off. And she plans to keep wearing one as she starts high school, even if it is far from fashionable.

For classmates who have always rejected masks, she doubts the change in CDC guidance will make a difference. After all, Forsyth County has already lifted all pandemic restrictions.

“If the county is saying that it’s safe, then kids are going to think it’s safe,” she said. “The CDC is not very well-regarded.”