RSV Seasonality and Climate

Despite increased warming and precipitation in Ireland consistent with climate change, post-pandemic RSV seasons still peaked earlier than historical norms, suggesting immunity debt dynamics outweigh climate effects. No single environmental variable has been definitively identified as the primary driver of RSV seasonality. Low temperature and high humidity are identified as key predictors of RSV epidemic activity. Local RSV seasons in some regions such as northern Brazil diverge substantially from standard Northern Hemisphere winter timing, making climate-adjusted immunisation scheduling locally important.