School Reopening Associated with Lower COVID-19 Case Rates Among Children

Strategic Insights -

Research conducted in the Fall of 2021, covering 3 weeks prior to and 12 weeks after school opening, has revealed a complex relationship between in-person schooling and the transmission of SARS-CoV-2 among children. The study, published in the International Journal of Epidemiology, aimed to estimate the relationship between school openings and COVID-19 case rates among children while accounting for potential confounders, such as community case rates, mitigations in schools, and rates of testing among schoolchildren.

Key Takeaways:

  • The study found that school openings were associated with a brief rise in cases among children relative to adults, with a peak of 39.3 (37.7, 40.9) additional cases per 100,000 per week.
  • However, children were tested at higher rates when schools were in session, which, after adjusting for testing rates, resulted in case rates among children being significantly lower after schools reopened by 4.7 cases per 100,000 compared with over summer break.
  • School reopening in the USA in the 2021-22 academic year was accompanied by an increase in SARS-CoV-2 testing in children and a brief rise in pediatric cases.
  • A lower threshold for testing in the school setting may be an important confounder in studies of SARS-CoV-2 transmission.
  • The study used restricted data obtained from the Centers for Disease Control and Prevention and was available for school districts in 2,592 counties, containing 86% of the US population.

Statistics:

  • 2,592 counties had data available for the study, accounting for 86% of the US population.
  • The peak number of additional cases per 100,000 per week among children relative to adults was 39.3 (37.7, 40.9).
  • After adjusting for testing rates, case rates among children were significantly lower by 4.7 cases per 100,000 compared with over summer break.

Sources:

  • International Journal of Epidemiology, 2025; 54(4).
  • Oxford Univ Press, Great Clarendon St, Oxford OX2 6DP, England.
  • ije.oxfordjournals.org
  • Oxford University Press, www.oup.com/
  • NewsRx. Massachusetts Institute of Technology Reports Findings in COVID-19 (School opening associated with lower test-adjusted COVID-19 case rates in children). Pediatrics Week. July 19, 2025; p 9.