The drivers of the RSV rebound during the COVID-19 pandemic.

You Li, PhD, Xin Wang, PhD, Bingbing Cong, BMed, Shuyu Deng, BMed, Daniel R Feikin, MD, Harish Nair, PhD

You Li and co-workers investigated why RSV has rebounded after the expected local RSV season in several countries during the COVID-19 pandemic. The RSV epidemic was late in the 18 countries included, and 11 observed a rebound before September 2021. The risk of observing a rebound of RSV was 23 times higher after re-opening schools. On the contrary, an increase in temperature of 5°C decreased the risk of RSV rebound by 37%. The risk of RSV rebound increased over time, suggesting a role of the accumulation of individuals susceptible to RSV through new births and waning immunity. Increased susceptibility of the population and full re-opening of schools may override the effect of high temperature. Countries that did not yet observe a rebound in RSV should prepare for it, especially in the weeks after re-opening schools and when temperature drops. This study will be instrumental for policy makers to understand impact of distinct non-pharmaceutical interventions to control the COVID pandemic.