The Importance of the Mask Mandate
On Friday, Sept. 24, the Center for Disease Control and Prevention released two studies providing evidence that mask mandates are effective in protecting children against COVID-19.
One study analyzed data on about 1,000 public schools in Maricopa and Pima counties, two of Arizona’s most populous counties. The study found that schools that did not require students and staff to wear masks were 3.5 times more likely to have a COVID-19 outbreak. The study defined an outbreak as two or more positive confirmed cases of infection among students and staff within a 14-day period.

Upon opening, only 21 percent of schools implemented a mask mandate for students and staff. However, an additional 30 percent implement a mask requirement 15 days following the start of school.
“The school year starts very early in Arizona, in mid-July,” an
associate professor at Arizona State University and a co-author of the study J. Mac McCullough said. “So we had the advantage of being able to get an early look at data for the new school year a bit sooner than was possible for the rest of the country, which was important, because of the transmission of the Delta variant.”
A second study examined infections amongst children in 520 counties across the United States during the first two weeks following the start of school. It found that in counties with school mask requirements, the average change in pediatric COVID-19 cases was 16.32 per 100,000/day, compared to 34.85 cases per 100,000/day in counties without school mask requirements. The study highlights that
pediatric COVID-19 cases increased at a significantly higher rate in counties where schools did not have mask mandates.
These studies provide additional evidence to support the effectiveness of the CDC’s Guidance for COVID-19 prevention in K-12 schools, guidelines to ensure safer in-person learning. In addition to mask-wearing, promoting vaccination of those eligible and screening testing are proven methods to work towards the end of the COVID-19 pandemic.