2024 Yes https://doi.org/10.1186/s12889-024-20623-5 Huang, Conghui North America Modeling Students Staff Elementary (K-5) Middle/Jr High (6-8) Viruses COVID rates Compartment model Primary and middle schools SARS-CoV-2 Within-school transmission Using a stochastic model, this study simulated SARS-CoV-2 spread in 116 Illinois school districts. Varying mask use and testing levels affected infection rates, highlighting the role of protective measures in sustaining safe in-person learning.