Maintaining masking requirements at Boston Public Schools protected students, staff

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an additional 44.9 COVID-19 cases per 1,000 students and staff in the 15 weeks after the statewide masking policy was rescinded. This represented nearly 12,000 total COVID-19 cases or 30% of all cases in those school districts that unmasked during that time, according to a new study led by Harvard T.H. Chan School of Public Health, the Boston Public Health Commission, and Boston University School of Public Health.