Upper Respiratory Infections in Schools and Childcare Centers Reopening after COVID-19 Dismissals, Hong Kong.

A large number of common cold outbreaks in Hong Kong schools and childcare centers during October-November 2020 led to territorywide school dismissals. Increased susceptibility to rhinoviruses during prolonged school closures and dismissals for coronavirus disease and varying effectiveness of nonpharmaceutical interventions may have heightened transmission of cold-causing viruses after school attendance resumed.