Studies highlight the importance of universal masking to stop COVID-19 spread in schools

Today, CDC released three studies in the Morbidity and Mortality Weekly Report (MMWR) that highlight the importance of using layered prevention strategies including universal masking to stop the spread and minimize disruptions to school operations for safe in-person education. These studies found that school districts without a universal masking policy in place were more likely to have COVID-19 outbreaks. Nationwide, counties without masking requirements saw the number of pediatric COVID-19 cases increase nearly twice as quickly during this same period.

One report from Arizona revealed that schools in two of the state's most populous counties were 3.5 times more likely to have COVID-19 outbreaks if they did not have a mask requirement at the start of school compared with schools that required universal masking on day one. Universal masking is an important component in the recommended layered prevention strategy for schools, and this study continues to demonstrate that facemasks when used as part of the larger strategy can reduce spread of COVID-19 and prevent outbreaks in schools.

Another report found that during the two weeks following the start of school, the average change in pediatric COVID-19 case rates was lower among counties with school mask requirements (16.32 per 100,000/day) compared with counties without school mask requirements (34.85 cases per 100,000/day). This highlights the impact that universal masking policies can have on the communities that surround these school districts, as the impact of the policies can reduce the burden on the health care systems that support these school districts.

A third report studied COVID-19-related school closures and found that despite an estimated 1,801 school closures so far this school year, 96% of public schools have been able to remain open for full in-person learning. The continued focus on providing students with a safe environment for in-person learning is one of the main priorities for CDC's guidance, and can be best achieved by following a layered prevention strategy.

These studies continue to demonstrate the importance and effectiveness of CDC's Guidance for COVID-19 Prevention in K-12 Schools to help districts ensure safer in-person learning and stop the spread of COVID-19. Promoting vaccination of eligible persons, mask wearing, and screening testing are all proven methods to continue to work towards the end of the COVID-19 pandemic.