In 2020, nonpharmaceutical interventions (NPIs) introduced to combat COVID-19 – such as lockdown policies, mandated social distancing, masking, and travel bans – dramatically impacted influenza virus transmission and evolution. Due to these interventions, cases of seasonal influenza caused by A subtypes H1N1 and H3N2, as well as influenza B subtypes Victoria and Yamagata, declined sharply across the globe.