Effect of Lifting School Mask Mandates on Covid-19 Incidence | NEJM

 

The removal of school mask mandates in Massachusetts led to a significant increase in COVID-19 cases among students and staff over a 15-week period.

Highlights
😷 Lifting mask mandates in schools resulted in a substantial rise in COVID-19 cases.
📊 A difference-in-differences analysis compared districts with and without mask mandates.
🏫 Boston and Chelsea Public Schools had similar COVID-19 trends before mask mandates were lifted.
📈 After lifting mandates, there was an additional 45 cases per thousand students and staff.
👩‍🏫 Staff showed a stronger protective effect compared to students.
💡 Approximately 29% of COVID-19 cases were associated with lifting mask requirements.
🧪 Detailed study results can be found at nejm.org.