Are masks effective for kids? Here’s what to know before school starts

Students lined up at the Hill School on the first day of classes in Revere on Wednesday, as the state issued a school masking mandate.Craig F. Walker/Globe Staff/The Boston Globe

Massachusetts public school students and staff members now will be required to wear a mask when they return for the new school year until at least Oct. 1 under a mandate issued Wednesday.

The edict applies to all children ages 5 and older; while students under 5 are not required to, the state strongly recommends they, too, wear masks. There are exceptions for students and staff who cannot wear a mask for medical reasons and for students who have behavioral concerns.

The ruling from state Education Commissioner Jeffrey Riley aligns Massachusetts with the prevailing guidance from the Centers for Disease Control and Prevention that children should be masked up in school as the Delta variant of COVID-19 triggers a resurgence of infections around the country.

Middle and high schools that can show at least 80 percent of students and staff are vaccinated by Oct. 1 can lift the mask mandate then, but only for those who are inoculated. Since vaccines have not been authorized yet for children under age 12, those students would continue to wear masks, meaning most elementary school educators for now would have to keep their masks on as well.

Some parent groups have pushed back against masks in schools, arguing face coverings can harm kids. But medical experts say masks are necessary to protect children who don’t have an available vaccine, and the benefits outweigh any potential drawbacks.

What do we know about masks and their effectiveness in schools?

The American Academy of Pediatrics — as well as many doctors and scientists — support universal masking policies as the best chance to keep schools safely open. A properly fitted mask that covers the nose and mouth reduces the amount of viral droplets in the air exchanged by people breathing or talking near each other, said Dr. Ibukun Kalu, a pediatric infectious diseases expert at Duke University Medical Center.

Several studies have shown the effectiveness of masks. One of the largest, conducted by the ABC Collaborative with Duke University, analyzed data from North Carolina public schools where masks were required. Researchers found that from March to June, 7,000 children and adults attended school while infectious with COVID, leading to 40,000 “close contacts” being quarantined. Of those, only 363 contracted the virus.

That low rate of in-school transmission was due in large part to masks, Kalu said, as most schools didn’t upgrade ventilation or socially distance students.

In contrast, 153 students and 25 staffers were infected at a school in Israel without a mask mandate or social distancing. And recent outbreaks at kids’ summer camps and schools in Georgia and Florida show how fast COVID can spread among unmasked, unvaccinated people, Kalu said.

“We saw that masking in the school environment reduced within-school transmission,” Kalu said. The Delta variant adds urgency to masks this year, she said, particularly for children under 12 who aren’t eligible for vaccination.

Even though children are at lower risk of severe disease and death compared to older people, Kalu said, both still happen: “COVID is still severe enough that if we can do what we can to prevent one case, we should, particularly if it’s something as low-impact as masking.”

What are the potential drawbacks of masks?

Some teachers, parents, and scientists are concerned about masks interfering with learning or development of social, language, and speech skills, especially for children who are very young or who already struggle.

While young kids do rely on watching mouths to learn to talk, they receive enough unmasked interaction during meals, playtime, and baths at home to develop language, according to an article published jointly by the American Academy of Pediatrics and the American Speech-Language-Hearing Association.

“Most of the interaction that a child is going to have in the language-learning phase is going to be at home with adults who are not wearing masks,” said Diane Paul, clinical director of speech language pathology for the American Speech-Language-Hearing Association.

After reviewing published scientific studies, the association found no evidence face masks interfere with speech and language development, Paul said.

She recommends masked teachers or caregivers follow good longstanding communication practices: facing the child and getting their attention before talking; speaking slowly and loudly; using eyes, hands, body language, and changes in tone; asking the child if they understood; and reducing distractions. Some educators also wear clear masks to help children who are hard of hearing read their lips.

Still, there is some disagreement over when it’s appropriate for kids to wear masks. The CDC doesn’t recommend children younger than 2 do. Meanwhile, the World Health Organization advises against masks for children 5 and under due to their lower susceptibility to COVID, challenges with correct usage, and the possibility that masks could interfere with their learning, socialization, and communication.

“The benefits of wearing masks in children for COVID-19 control should be weighed against potential harm associated with wearing masks, including feasibility and discomfort, as well as social and communication concerns,” the WHO said.

Daniele Lantagne, an infectious diseases expert at Tufts University who helped develop the WHO’s child-masking guidance, said many young kids like her own have no trouble wearing masks and should just wear them in schools. But some others struggle because they’re very young or they have disabilities or developmental delays. They should be allowed to forgo masks with distancing or other measures, she said. The state mandate allows such exceptions in schools.

For children ages 6 to 12, the WHO recommends considering local COVID levels and the potential impact of mask wearing on learning and social development.

Some countries are focusing school-safety strategies more on testing as they feel masking interferes with teacher-child communication, Lantagne said. Because in part of the WHO guidance, many European countries such as England, Norway, Ireland, and Switzerland are not requiring masks, or in some instances even advising against them, for elementary-age children.

Local and state masking guidance should be reassessed every two to three months amid changes in the COVID picture, Lantagne said.

“Right now, we’re relatively high-transmission,” Lantagne said. “We need to shy away from, ‘We’re just going to put masks on kids for the next five years.’ ... There may be longer-term impacts on speech.”

Health experts emphasize the trade-off is worth it to save lives.

“The benefits clearly outweigh the downsides in a deadly pandemic where more than 400 children have died,” said Dr. Paul Offit, a pediatric infectious diseases and virology expert at the Children’s Hospital of Philadelphia. “It’s not your civil liberty to catch and transmit a potentially fatal infection. It’s not a personal choice; it’s a choice you make for other people.”

Should vaccinated students in highly vaccinated communities still have to wear masks?

Experts disagree on this question. The CDC has advised everyone to wear masks in schools, regardless of vaccination status, citing evidence that vaccinated people can still become infected and probably spread COVID, though they face far lower personal risks of severe disease, hospitalization, and death.

But under new rules, the Baker administration has said middle and high schools with more than 80 percent of students and staff vaccinated by Oct. 1 can lift their masking mandates.

Lantagne said removing school mask mandates in such instances could be fine in conjunction with other safety measures.

“If there are not that many cases in the community and high vaccination rates, you can say, ‘We can reduce the number of layers of protection,’” she said.

But Kalu said masking still would be an important way to keep vaccinated students in school learning.

“It is reassuring when you live in a community that has high vaccination rates for children and adults,” Kalu said. “However if masking is voluntary, it will likely be much less effective at preventing transmission and much less effective at preventing quarantine, which has also been a huge burden on the K-12 school environment.”