Risk Assessment of COVID-19 Airborne Infection During Hybrid Learning

Converging lines of evidence seem to indicate that SARS-CoV-2, the novel coronavirus responsible for the COVID-19 pandemic, can be transmitted from person-to-person via aerosols that waft through the air and accumulate over time. The airborne nature of the virus could be a threat in indoor spaces in general and in particular for in-class education. We provide an assessment of the risk of SARS-CoV-2 infection during a 7-hour school day in elementary schools. We show that existing data are insufficient to establish a low (below 1%) probability of infection with high accuracy. The use of facemasks and social distancing could significantly decrease this risk.