Schools with universal masking report fewer COVID-19 cases, studies show

K-12 schools that required universal masking reported significant reductions in COVID-19 cases last year during the delta wave of the pandemic, according to two studies published this week.

In Pediatrics, researchers reported results from a study conducted in more than 60 school districts that showed there were 72% fewer COVID-19 cases in schools with a universal mask requirement compared with schools that had a mask-optional policy.

A second study published in MMWR found that schools in Arkansas with universal mask requirements reported 23% fewer cases than those without.

The observational cohort study published in Pediatrics took place in the last 6 months of 2021. It included 1,112,899 students and 157,069 staff from 61 K-12 school districts in nine states. Of the districts, 46 had universal masking policies, nine had partial masking policies and the remaining six had optional masking policies.

From July 26 to Dec. 13 the school districts reported 40,601 primary and 3,085 secondary infections. The researchers reported that districts with optional masking throughout the study period had 3.6 times the rate of secondary transmission as universally masked districts.

“We found that overall rates of secondary transmission were modest, and that universal masking policies were associated with markedly reduced secondary transmission compared with optional masking districts,” they wrote.

The other study examined cases that occurred in 233 K-12 school districts in Arkansas from Aug. 23 to Oct. 16 and found that “school mask policies were associated with lower COVID-19 incidence in areas with moderate to substantial community transmission,” the authors wrote.

“Maintaining in-person instruction is critical for children,” they wrote. “Providing districts with the tools to monitor transmission data in real time enables schools to respond to changing national and local policies, as well as adjust their mitigation efforts to keep in-person education as safe as possible for the remainder of the COVID-19 pandemic.”

The AAP says masking in schools is still “an “important layer of protection” for children. Last month, the CDC released new COVID-19 guidance indicating that most Americans live in areas where they can go maskless. That came after many states, including New Jersey and Delaware, said they would lift COVID-19 mask mandates in K-12 schools. The latter move was criticized at the time by the AAP as coming “too early.”

References:

Donovan C, et al. MMWR Morb Mortal Wkly Rep. 2022;doi:10.15585/mmwr.mm7110e1.