Another wave of coronavirus cases is sweeping across the country and schools nationwide are shifting back to virtual classes.

Based on a growing body of evidence, researchers suggest that schools do not serve as hot spots or major points of spread for COVID-19. Instead, they argue the number of cases in schools reflect both the infection rates and social distancing policies of their surrounding communities. The data suggests schools can remain open to in-person instruction with adequate policies in place.

Democratic Kentucky Gov. Andy Beshear switched his state to online-only learning on Monday, joining New York City Bill de Blasio and Democratic Michigan Gov. Gretchen Whitmer who implemented similar measures. The rate of online-only instruction across the U.S. sits around 40%, according to USA Today.

Beginning tomorrow, November 19, @NYCSchools buildings will close for in-person learning due to a 3% COVID-19 positivity rate in New York City. @NYCMayor provided an update: pic.twitter.com/lIOg5O8bhf

— City of New York (@nycgov) November 19, 2020

Sallie Permar, a professor of pediatrics and immunology at Duke University, told the Association of American Medical Colleges (AAMC) that — so far — schools have not acted as the spreader sites previously feared.

“What we haven’t seen are superspreader events. The fear that you’d have one infected kid come to school, and then you’d have many other kids and teachers and relatives [at home] get infected — that hasn’t happened,” Permar said.

What happens outside the classroom, then, is critical to virus spread at a school, according to experts. (RELATED: Recent Studies Suggest Opening Schools Might Make ‘Absolutely No Difference’ In Spread Of COVID-19)

Benjamin Linas, an associate professor of medicine and epidemiology at Boston University, told AAMC that schools should only be opened when the outside community enacts plans to control virus spread. The actions taken by a school to prevent outbreaks should be a function of a broader community plan, according to Linas.

Peggy Thompson, director of infection prevention at Tampa General Hospital, explained to AAMC that even the best planning in schools cannot be the only part of community implemented good social practices.

“You can have the best laid plans [but] if kids are not following social distancing and mask usage outside of school, they’re going to bring COVID into the school with them,” Thompson said.

Teachers unions have pushed back on reopening plans. Prior to school openings, Randi Weingarten, president of the American Federation of Teachers, said that no action was “off the table” when it came to the safety of students and teachers. Similarly, the head of the National Educators Association Lily Eskelsen García reinforced Weingarten’s approach.

“Nobody wants to see students back in the classroom more than educators, but when it comes to their safety, we’re not ready to take any options off the table,” Garcia said.

Emily Oster, an economist at Brown University, analyzed data from schools across 47 states during the last two weeks of September. Out of more than 63,000 staff and 200,000 students tested, Oster’s study found an infection rate of 0.13% among students and 0.24% among school staff.

Oster wrote in a Nov. 20 op-ed for the Washington Post that attempts to curb the virus should be aimed at the larger community rather than completely focused on a school.

“The best available data suggests that infection rates in schools simply mirror the prevalence of covid-19 in the surrounding community — and that addressing community spread is where our efforts should be focused,” Oster said.

Oster explained that schools often do not distinguish where a student who tests positive while in school may have contracted the virus. Thus reported cases should not be the deciding factor in the argument to close schools. Administrators should worry when in-school infections surpass what’s going on outside the school.

“The prevalence of covid-19 detected in schools, in other words, shouldn’t be any different than if coronavirus testing were conducted among populations at local grocery stores or restaurants or gyms or public parks,” Oster said.

Detailed data from NY lets us map out COVID in schools & community. With graphs. Nice graphs!https://t.co/R7h559JnhZ

— ProfEmilyOster (@ProfEmilyOster) November 20, 2020

Ashish Jha, dean of the Brown University School of Public Health, wrote in a Nov. 19 op-ed for the Washington Post that communities must rely on updated data to inform their decisions. Previous arguments, Jha wrote, were made based on models of expected viral spread, but now leaders have real world “examples of schools at all grade levels being managed safely and effectively.”

“While there have been some outbreaks in contexts without strong mitigation measures, there is no evidence suggesting spread within schools when effective mitigation measures are in place,” Jha said.

Jha said there are potential negative health consequences that school closings might have on students, adding that schools “fill vital essential functions in our society—education, child care and provision of nutrition and health.”

“Despite the best efforts of education districts, there is no doubt that remote instruction generates large learning gaps and links to higher rates of mental illness, while depriving children of formative social and peer relationships,” Jha said.

Danielle Dooley, a medical director at Children’s National Hospital in Washington, D.C., echoed Jha’s beliefs that keeping kids out of school can have serious consequences.

“As a pediatrician, I am really seeing the negative impacts of these school closures on children,” Dooley told NPR. “Going to school is really vital for children. They get their meals in school, their physical activity, their health care, their education, of course.”