Two studies released Friday support the agency’s recommendation for universal indoor masking in schools.
For the first study, researcher looked at data covering about 1,000 K-12 schools in Arizona’s Maricopa and Pima Counties, which are home to more than three-quarters of the state’s population.
A school was considered to have a masking requirement if all people — including students, staff, faculty and visitors — were required to wear a mask indoors, regardless of vaccination status. A school was considered to have an outbreak if there were two or more news cases among students or staff within a 14-day period, beginning a week after school started.
From mid-July through the end of August, 191 school-associated outbreaks occurred, according to the CDC. Schools with universal masking requirements in place at the start of school accounted for about 31% of the set of schools analyzed, but only about 8% of outbreaks. Meanwhile, schools with no masking requirement accounted for 59% of those outbreaks, but less than half (48%) of the total set of schools analyzed.
In early August, the CDC adjusted recommendations for masking in schools to include everyone, regardless of vaccination status, due to the prevalence of the more contagious Delta variant.
“I would say that data actually absolutely show that masking decreases outbreaks in schools,” CDC Director Dr. Rochelle Walensky said Monday. “So with the purpose of keeping our kids in school, getting them in school, having them be safe, masks really are the way to go.”
Another CDC study published Friday suggests that the effects of masking policies in schools appear to extend beyond classroom walls, too.
The study found that case rates among children increased more in counties where schools did not have mask requirements than they did in counties where schools mandated universal masking.
Between the week before school started and the week after school started, pediatric case rates increased more than twice as much in counties with no school mask requirements as they did in counties with school mask requirements.
Counties without school mask requirements added an average of about 35 new pediatric cases per 100,000 children each day over that two-week span, compared to a growth of about 16 new pediatric cases per 100,000 children each day in counties with school mask requirements.
For this study, the CDC analyzed pediatric case rates in about 500 counties in which mask requirements were consistent for all schools in the county and were applicable to either all students or no students….
Read More: Masks in school help prevent Covid-19 outbreaks and spread, CDC studies