Very few kids are getting COVID-19 after going back to primary school, research shows - but masks are key

• Kids attending school in person have, for the most part, avoided the coronavirus — as long as masking and social distancing are required.
• Schools in Norway and Sweden have seen few coronavirus cases — even without mask requirements — when community transmission rates are low.
• The studies suggest that schools can reopen safely if they take appropriate public-health measures.

Dozens of North Carolina schools reopened their doors in August. The in-person learning environment was slightly different than in pre-pandemic days: Students age 5 and up were required to wear masks, stay six feet apart, and wash their hands regularly.

But the gamble paid off. By the end of October, relatively few students or staff had gotten sick, according to a study published in the journal Pediatrics.

The researchers, from Duke University and the University of North Carolina at Chapel Hill, evaluated 11 school districts in their state, with a total of nearly 100,000 students and staff members, for nine weeks. More than 770 of those individuals tested positive for the coronavirus during that time, but only 32 infections were recorded in schools.

The findings were surprising given the rate of coronavirus transmission in North Carolina at the time. From August to October, the 11 counties in the study recorded roughly one to two weekly coronavirus infections per 1,000 residents. If schools had that same level of transmission, they would have seen 800 to 900 infections over the same nine weeks.

"If you do mitigation strategies, it's safer for kids and adults to be in school than to be in the community," Daniel Benjamin, one of the study's authors, told Insider.

Indeed, a spate of recent studies has found schools to be relatively low-risk compared to other places where people congregate, like household gatherings or college dorms.

A new report from the Centers for Disease Control and Prevention also identified very few coronavirus cases among K-12 schools that required masks in Wood County, Wisconsin.

Out of 5,530 students and staff members, only 191 COVID-19 cases were reported between August and November. Just seven of those cases were associated with in-school transmission - and all of them were students. By comparison, the virus was spreading rampantly in the community: Up to 40% of COVID-19 tests in Wood County had positive results during the study period.

The researchers concluded that "with proper mitigation strategies, K-12 schools might be capable of opening for in-person learning with minimal in-school transmission."

In an editorial on Tuesday, CDC researchers similarly called for schools to reopen with mask and social distancing requirements.

When community transmission is high, masks are essential in schools

Schools come with known coronavirus-transmission risks, since most are poorly ventilated indoor spaces that hold groups larger than 10. But research has also shown that young children are less likely to develop symptomatic COVID-19 infections than adults, and may also be less likely to pass the virus to others.

Benjamin said the number of infections in schools depends on the level of commitment to masks, hand washing, and social distancing.

"It's not about the school and physical environment - it's about the school leadership and culture," he said.

When community transmission is low, schools might even get away with fewer precautions. Schools in Norway and Sweden, for instance, have managed to keep cases low by encouraging social distancing and telling kids to stay home if they have any COVID-19 symptoms.

A recent study looked at transmission in primary schools in Oslo and Viken, the two Norwegian counties with the country's highest COVID-19 case totals. From August to November, 234 children were tested for the virus but only two cases were identified. None of those students appeared to pass the virus to anyone else, even though masks weren't required.

The researchers concluded that children played a "limited role" in spreading the virus at schools during a time of "low to medium community transmission."

In Sweden, researchers also found a low incidence of severe COVID-19 infections among schoolchildren: From March to June, only 15 kids between ages 1 and 16 were admitted to Swedish intensive care units with COVID-19. Four of them had underlying health problems, according to research published in the New England Journal of Medicine.

But Benjamin cautioned that schools that don't require masks are "going to be in for a rude awakening" as they grapple with the new coronavirus strains identified in the UK and South Africa, which appear to spread more easily.

"When cases go up, they will either need to mask or they're going to have real problems," Benjamin said.

A cautious approach to reopening

President Joe Biden has set a goal of reopening most K-8 schools during his first 100 days in office.

"We can teach our children in safe schools," Biden said in his inaugural address.

Biden's proposed coronavirus relief plan would allocate $130 billion to help primary schools reopen safely. Schools could use that money to improve ventilation, reduce class sizes, hire more janitors, distribute personal protective equipment, or modify classroom layouts so students and teachers can socially distance.

More funding could also enable schools to expand their testing capacity - though Benjamin said that shouldn't be a substitute for other health measures.

"Whether testing prevents more infection is a different question, not yet answered in the K-12 environment," he said. "What testing definitely does do is it shows whether or not your public-health mitigation strategies are effective."

Benjamin said schools may also consider a hybrid approach that offers remote learning for families who are worried about infections alongside in-person classes.

An analysis from McKinsey & Company suggests that American students, on average, are likely to lose five to nine months' worth of learning by June 2021 due to the pandemic. Achievement gaps between students will also widen, Benjamin said, the longer classrooms stay closed.

This story has been updated with additional information. It was originally published on January 22, 2021.