2024 Yes A multi-layered strategy for COVID-19 infection prophylaxis in schools: A review of the evidence for masks, distancing, and ventilation https://onlinelibrary.wiley.com/doi/10.1111/ina.13142 McLeod, Robert S. Multiple Countries Review Teachers Staff Students Elementary (K-5) Middle/Jr High (6-8) High School (9-12) Viruses Ventilation rates Air purification infection prophylaxis in school classrooms Masking and physical distancing Mechanical ventilation natural ventilation. Maintaining safe in-classroom teaching during COVID-19 requires layered prevention: masks, distancing, ventilation. Effectiveness depends on variant threat, community spread, and risk tolerance. Masks, testing, and ventilation notably reduce transmission risk. 2022