The results of a study released by University of Utah Health suggest that in most regions, with the exception of the South, opening schools for in-person learning was not associated with an increase in COVID-19 case rates in the community. The results of the nationwide study, published in Nature Medicine, included 895 school districts across the United States.

“The results suggest it is possible for schools to operate safely and in-person without increasing case rates in the community,” said Richard Nelson, associate professor of epidemiology at University of Utah Health and co-senior author with Dr. Westyn Branch-Elliman of the VA Boston Healthcare System. “But the flip side is true, too. In some areas, in-person school did appear to be a source of community spread.”

The researchers analyzed data gathered during the 12 weeks from July to September 2020 by region, and categorized them as the Northeast, Midwest, South and Mountain West. The Pacific West was not included because nearly all public schools were virtual.

The study found that in every region analyzed, COVID-19 cases increased during the weeks following the start of school. The South was the only region where case rates were higher in counties with in-person or hybrid school as compared to counties with virtual learning, after controlling for other contributing factors. In all other regions, community case rates during the period following school opening were similar regardless of whether school was virtual, hybrid or in-person.

“We know that cases increased substantially last fall throughout the country,” Nelson says. “In some areas of the country, school mode was a contributing factor to those increasing rates, whereas in other areas it was not.”

The researchers adjusted results for local policies, including closings of workplaces and public transportation, canceling of public events, COVID testing and contact tracing policies and mask requirements.

At the time the study data were collected, vaccinations were not available and the delta variant had not yet emerged in the U.S. Additional research will also need to investigate how these factors affect the spread of COVID-19, study authors said.