Since the earliest days of the pandemic last March, debate has raged over whether U.S. schools are a significant source of COVID-19 transmission and should remain closed—or if in-person learning can, and should, continue with safety protocols in place. Experts have expressed increasing concern over the downsides that prolonged virtual instruction might pose for academic and social development in children—especially kids in disadvantaged communities who were already struggling before the pandemic. Now, more than a year after schools around the country first shut down, many experts agree they can remain open safely if they implement measures such as mask wearing, physical distancing and good ventilation.

Studies of school districts in states such as Florida, Utah and Missouri found that in-person instruction did not lead to a noticeable spike in COVID cases. The U.S. Centers for Disease Control and Prevention recently updated its guidelines to say that three feet of distancing (as opposed to the six feet recommended earlier) is sufficient to limit transmission among elementary school children—and among middle and high school kids when community transmission levels are low—as long as masks are worn. The guidelines also emphasize the importance of universal mask wearing and good ventilation and recommend having “cohorts” of students that spend the day together and maintain distance from other cohorts. About 80 percent of teachers and school staff members have now received at least one vaccine dose, according to the CDC. Although the vaccines are not yet available to children, clinical trials involving them are underway.

Evidence suggests that the benefits of having kids in school—with precautions in place—strongly outweigh the risks, especially now that most teachers have been vaccinated. “The goal has to be to get kids back to in-person learning,” says Sara Bode, a member of the American Academy of Pediatrics (AAP) Council on School Health’s executive committee. “There has been a mounting body of evidence over the past year of schools being able to put mitigation strategies into place and not seeing much student-student spread. It can be done, and it can be done effectively.”

A layered approach is essential when it comes to lowering the COVID transmission risk in schools, says Greta Massetti, co-lead of a CDC task force on the agency’s response to COVID, including school guidance. “Young children are going to pull their masks down sometimes or not wear them properly or not wash their hands,” she says. So “you’re not relying on any one layer. It’s the ‘Swiss cheese model.’” Some epidemiologists have used this metaphor to describe imposing multiple public health interventions at once: each “slice” has “holes,” but stacked together, they improve protection.

Perhaps the most important measure schools can take to keeps kids and staff safe is the universal use of face masks at all times, except when eating or drinking. The CDC recommends that students maintain at least six feet of physical distance when masks are off. “Many schools are doing very creative things during mealtimes: establishing routines so students keep their masks on until they are ready to eat, then putting them back on; seating kids facing in the same direction; staggering lunch schedules; and having half the class go to the cafeteria and half eat in the classroom,” Massetti says. Studies have shown that even young children can wear masks properly. One study in Wisconsin found that more than 92 percent of students reported wearing a mask consistently while at school. “Many times, they’re better than adults,” Massetti says. But schools must clearly mandate masks, she adds. “When they make it optional, then nobody wears a mask,” Massetti says.

Masks are also very effective at protecting faculty and staff. “If schools require masking and do hand hygiene, the risk of mortality from driving to work [and having a traffic accident] is higher for an unvaccinated adult than it is from acquiring COVID in school,” says Danny Benjamin, a professor of pediatrics at Duke University School of Medicine. Benjamin and his colleagues co-authored a study of coronavirus transmission in K–12 schools in North Carolina that had in-person classes between mid-August and mid-October, 2020. The study found in-school transmission of the virus was extremely limited, and there were no observed cases of kids infecting adults. Other studies have found similar results in Mississippi, Wisconsin and additional states. “It’s pretty simple: if everybody wears a mask all the time, the risk is low,” Benjamin says. “For us to be keeping schools closed because of the risk of COVID is simply malpractice.”

Benjamin acknowledges, however, that some schools have not taken masking and other public health measures seriously. “The data from [some parts of] Florida are a good way to quantify risk,” he says. “They have a whole lot more COVID than they need to” in school districts without a mask requirement and in ones that reopened sooner. It is not clear how many of Florida’s cases among students and school staff were acquired in a school versus in the broader community. Even if there are high levels of community transmission, however, Benjamin says schools can still stay open safely if they take precautions.

Improving ventilation is another way schools can reduce COVID risk. “The bottom line is: air exchange is essential,” the CDC’s Massetti says. There are many ways to address this, such as upgrading HVAC (heating, ventilation and air-conditioning) systems, changing air filters more often, using fans or opening windows. Not all schools have adequate resources for such measures, though. Having students stay outdoors as much as possible is also helpful, but few schools are able to do that year-round. “There is no one-size-fits-all approach,” the AAP’s Bode says.

If a student or teacher does contract COVID, testing and contact tracing are crucial for schools to prevent one case from becoming many. “It’s really not practical to have repeat, universal asymptomatic testing, nor do I think that’s necessary with all the other mitigation strategies,” Bode says. “What [schools need] is a really nice, effective way to identify kids quickly that are having symptoms ... for families to quickly get that testing [and] get the child either back into school the next day—if they don’t have COVID—or get them isolated quickly, and then do that contact tracing.”

The drawbacks of children not being in school are numerous. More than half of educators at U.S. public schools reported “significant loss of learning” among students over the past year, and another 44 percent reported “some loss,” according to a March report by the Horace Mann Educators Corporation. And the gap is not just in academics but also in social-emotional learning, the report concluded. A study by McKinsey & Company found the learning gap is especially big for students of color, who were about three to five months behind at the start of classes last fall, compared with one to three months for white students.

There are big disparities among households in terms of factors that affect kids’ ability to succeed at virtual learning. They range from having a stable Internet connection to whether parents are able to take time off to help their children with schoolwork. “We are creating a disparity of academics because some kids don’t have a rich home environment,” Bode says. There are reasons why children go to school in person, she says, including the back-and-forth discourse and hands-on activities, the social-emotional growth, and the interactions with peers and adults who are not their parents. “All of that is so critical, and kids are missing out on that as the months go by,” Bode says. “And it’s really going to have long-lasting effects for these kids if we can’t get them back into the classroom.”

Online schooling has worked particularly well for a small subset of children, according to Benjamin. “Kids who were going to be wildly successful in person—they’re doing fine,” he says. These children’s parents have hired tutors and arranged learning pods, and they are spending lots of time teaching the kids themselves. But for children who were already suffering academically, “the chasm and achievement gap is getting a lot worse,” Benjamin adds. He notes that in some states, more children have died by suicide than from COVID in the past year, although nationwide data for 2020 are not yet available. “If you want harm children,” he says, “keep schools closed.”

Things may be improving. As of late March, nearly half of U.S. school campuses were open, and as of early April, at least 12 states required full- or part-time in-person instruction for some grades. Late last year President Joe Biden said that he wanted the majority of schools open for full-time in-person learning by the end of his first 100 days. Most teachers have been vaccinated for COVID-19, and many states are now allowing anyone age 16 and older to receive a vaccine as well. Vaccinations for younger teenagers may be available in the coming weeks, and it is possible that those for preteens could begin by early next year.

Massetti has three teenage children who all began in-person classes a few weeks ago. “The very first day they came home, I was very nervous about how they would react,” she says. But “they all were thrilled. They felt like they got to know their teachers better in-person in one day than they had over a semester and a half of virtual. I think they really welcomed the experience and are glad to be back in school.”

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