Pediatric COVID-19 Cases in Counties With and Without School Mask Requirements - United States, July 1-September 4, 2021

MMWR Morb Mortal Wkly Rep. 2021 Oct 1;70(39):1377-1378. doi: 10.15585/mmwr.mm7039e3.


Consistent and correct mask use is a critical strategy for preventing the transmission of SARS-CoV-2, the virus that causes COVID-19 (1). CDC recommends that schools require universal indoor mask use for students, staff members, and others in kindergarten through grade 12 (K-12) school settings (2). As U.S. schools opened for the 2021-22 school year in the midst of increasing community spread of COVID-19, some states, counties, and school districts implemented mask requirements in schools. To assess the impact of masking in schools on COVID-19 incidence among K-12 students across the United States, CDC assessed differences between county-level pediatric COVID-19 case rates in schools with and without school mask requirements.

MeSH terms

  • Adolescent
  • COVID-19 / epidemiology*
  • COVID-19 / prevention & control*
  • Child
  • Child, Preschool
  • Humans
  • Masks / statistics & numerical data*
  • Schools / statistics & numerical data*
  • United States / epidemiology