Mask requirements for schools have sparked controversy in many parts of the country. Now, two studies published Friday by the Centers for Disease Control and Prevention are providing additional evidence that masks protect children from the coronavirus, even when community rates are high and the contagious Delta variant is in circulation.
A study conducted in Arizona of children returning to school in July found that schools that did not require masks for staff and students were 3.5 times more likely to be affected by a virus outbreak than schools that required universal masking .
A second study looked at infections in all children in 520 different counties in the United States and found that by the start of the public school year, pediatric cases rose much faster in counties where schools did not require masks.
The first study analyzed data from approximately 1,000 public schools in Maricopa and Pima counties, which include the Phoenix and Tucson metropolitan areas and which make up most of the state’s population.
Only 21 percent of schools implemented a universal mask mandate when they opened, and almost half had no mask requirement at all. Another 30 percent introduced compulsory masking around 15 days after school started.
Between July 15 and August 31, there were 191 school-associated virus outbreaks that occurred about a week after school started. Most of them – 113 outbreaks, or nearly 60 percent of the total – occurred in non-mask schools.
Only 16 outbreaks, or 8 percent of the total, occurred in schools that introduced mask requirements from the start, regardless of vaccination status. In schools that had made masking compulsory after the start of the school year, there were 62 outbreaks, or about a third of the total.
The study defined an outbreak as two or more positively confirmed cases of infection in employees or students within a 14-day period.
“The school year in Arizona starts very early, in mid-July, so we had the advantage of being able to take a look at the data for the new school year a little earlier than was possible in the rest of the country because of the transfer of the Delta variant important Said J. Mac McCullough, Associate Professor at Arizona State University and co-author of the study.
The CDC recommends a layered approach to preventing coronavirus outbreaks in schools – masking, distancing, staying home when sick, and vaccinating for eligible individuals. “This study really sheds light on the masking part of it,” said Dr. McCullough.
The second study examined the relationship between school mask guidelines in a given county and community-wide infections in children, and found that counties without school masking had a greater increase in pediatric case numbers after school than counties with school masking.
Between the week before school starts and the second week of school, the number of pediatric infections in counties without a mask requirement rose by 35 cases per 100,000, while the number in counties with a school mask requirement rose by 16 cases per 100,000 inhabitants.