Closing schools in March may have saved the lives of 40,000 Americans, a new analysis found

• A new study analyzed the effects of early school closures in response to the spread of coronavirus in the US.
• The study found that the closures may have prevented over 1 million COVID-19 cases and saved more than 40,000 lives.
• But the study authors said other interventions likely played a role, too.

As autumn approaches and the coronavirus continues to spread in the US, educators and politicians face a difficult choice: Whether or not to bring students back to school.

There are strong arguments on both sides: On the one hand, schools can facilitate transmission of the virus, since many are poorly ventilated, and classrooms and restrooms offer little room for social distancing. On the other hand, kids rarely die from the coronavirus, and schools provide them with crucial social engagement, education, and stability.

Closing schools can also cut off students' access to meals, and researchers have estimated that such closures could cause substantial earning losses for affected students later on in life. That's not to mention the lost earnings and productivity for parents who have to spend time caring for kids at home while school is remote.

"There really have been substantial public-health negative consequences for children not being in school," CDC director Robert Redford said in a Friday press conference. "You are going to see that the public-health benefit is far greater by getting these schools reopened."

Those who disagree, however, cite young people's potential to spread the virus to more vulnerable people in their communities.

A study published in the Journal of the American Medical Association on Wednesday attempted to quantify how much closing schools curbed coronavirus transmission and, consequently, prevented deaths. The findings are stark: School closures may have prevented 1.37 million cases of COVID-19 in the country between day 17 and day 42 of schools' closure periods. The researchers estimated that 40,600 fewer Americans died overall during that period because schools shuttered.

Overall, the study showed, school closures may have reduced the rate of new cases by 62%. If schools had stayed open, an estimated 639 people out of every 100,000 people would have gotten infected, but in reality, there were just 215 cases per 100,000 people.

States that closed schools earliest saw the strongest effect, the researchers found, with a 72% decrease in the rate of new COVID-19 cases; states that closed schools later in the pandemic saw a decrease of about 49%.

Additional factors could influence these figures

For the new study, researchers from Cincinnati Children's Hospital Medical Center gathered data on coronavirus incidence rates and deaths in all 50 states between March 9 and May 7. They compared the rates of coronavirus cases per 100,000 people in each state against the dates those states' school closures went into effect. Then, using statistical models, they predicted what would have happened if schools had remained open.

Because many factors affected coronavirus case numbers in each state, of course, the researchers' models took into account stay-at-home orders, closures of nonessential businesses like bars, and bans on gatherings of more than 10 people. Their analysis also factored in the availability of testing in each state as well as factors like the number of nursing-home residents and racial demographics.

Isolating the effects of school closures from those other factors is difficult, however, so the researchers say it's likely they didn't isolate the variables perfectly, or might have missed a few. For that reason, they caution that their figures are estimates.

They also noted that school closures didn't just stop children from gathering — they also disrupted adults' schedules, making it more difficult for them to engage in social activities or work outside the home. So it's possible that school closures curbed transmission primarily by keeping parents from mingling, not their kids.

Decisions about reopening schools are immensely challenging

The new findings come at a turbulent time for many school officials. While the CDC has issued guidelines for reopening schools and has encouraged them to reopen, many school districts are still hashing out their plans.

Some have already announced that they won't fully reopen. At least one New Jersey school district has proposed that students go back to school just one half day per week. One of the largest teacher unions in the country, the American Federation of Teachers, has said it will support local chapters that decide to strike over their districts' reopening plans.

An editorial published alongside the new study urges local and federal officials to take the researchers' findings into account when considering whether and how to reopen schools. If schools do reopen, it says, the government should fund more research into measures that can help keep children safe.

"The decision to reopen schools for in-person educational instruction during the fall of 2020 is among the greatest challenges that the US has faced in generations," they wrote. "Federal agencies should prioritize funding for research that facilitates rapid learning about which practices are most effective in educational settings."