Maintaining Masking Requirements in Boston Public Schools Protected Students, Staff during 2021-22 School Year.
Maintaining Masking Requirements in Boston Public Schools Protected Students, Staff during 2021-22 School Year
Districts that lifted masking requirements saw significant increases in COVID-19 cases among students and staff, compared to Boston.
The lifting of masking requirements in school districts outside of Boston in February 2022 was associated with an additional 44.9 COVID-19 cases per 1,000 students and staff in the 15 weeks after the statewide masking policy was rescinded, according to a new study by Boston University School of Public Health, Harvard T.H. Chan School of Public Health, and the Boston Public Health Commission.
Published in the New England Journal of Medicine (NEJM), these findings represented nearly 12,000 total COVID-19 cases, or 30 percent of all cases in those school districts that unmasked during that time.
“This study provides clear support for the importance of universal masking to reduce transmission of COVID-19 in school settings, especially when community COVID levels are high,” says study co-author Eleanor Murray, assistant professor of epidemiology at Boston University School of Public Health. “Masking reduces COVID-19 transmission in schools in an equitable and easy to implement way and should be part of any layered mitigation strategy.”
“Our study shows that universal masking is an important strategy to reduce transmission in schools and one that should be considered in mitigation planning to keep students and staff healthier and minimize loss of in-person school days,” says Tori Cowger, corresponding author and Health and Human Rights fellow in the FXB Center for Health and Human Rights at Harvard Chan School. “Our results also suggest that universal masking may be an important tool for mitigating structural inequities that have led to unequal conditions in schools and differential risk of severe COVID–19, educational disruptions, and health and economic effects of secondary transmission to household members.”
When Massachusetts rescinded its statewide universal masking policy earlier this year, many schools in the state, including those in the Greater Boston area, lifted their requirements over the next several weeks. However, two school districts—Boston and Chelsea—maintained universal masking policies through June. That staggered lifting of masking requirements gave the researchers the unique opportunity to examine the impact of lifting those requirements on the incidence of COVID-19 among students and staff across 72 school districts in the greater Boston area.
The researchers found that before the statewide masking requirements were lifted, the trends in the incidence of COVID-19 observed in the Boston and Chelsea school districts were similar to the trends in the districts that later lifted masking requirements. After the statewide policy was rescinded, the trends diverged, with a substantially higher incidence observed in districts that lifted masking requirements compared to districts that maintained their masking requirements.
The findings also showed that the effect of school masking policies was greatest during periods when COVID-19 incidence was highest in surrounding cities and towns, suggesting that implementing universal masking policies during times of high transmission would be most effective.
In an accompanying NEJM editorial to the study, Julia Raifman, assistant professor of health law, policy & management, emphasizes that the study exposes the “fundamental logical flaw” of individual masking: that individuals will shoulder the full costs of their own masking decisions, rather than others. “Strategic implementation of masking policies requires consideration of the costs of not masking—and who will bear those costs,” writes Raifman, who co-authored the editorial with Tiffany Green, assistant professor in the Departments of Population Health Sciences and Obstetrics & Gynecology at the University of Wisconsin-Madison School of Medicine and Public Health. “‘The questions for policymakers are these: how high will we allow the societal costs to be, and who will bear the greatest costs?'”