The changing influenza activity in the Southern hemisphere countries during the COVID-19 pandemic

Abstract Introduction While the reduction in influenza cases in the Northern hemisphere during 2020 has been widely reported, the Southern hemisphere’s influenza transmission dynamics remain uncharacterized. Methods We analyzed the change in the influenza-positive proportions (IPP) between 2010–2019 and 2020 in Southern hemisphere countries with ≤40% missing IPP data from FluNet to assess the coronavirus disease 2019 (COVID-19) relates to influenza activity. Our analysis considered the COVID-19 incidence reported by the World Health Organization and the implementation date of non-pharmaceutical interventions (NPIs) reported by the Oxford COVID-19 government response tracker. Results In each of the seven included countries, in 2020, the average IPP was lower than before (p  Conclusions Influenza burden and activity decreased during 2020 in the Southern hemisphere. The temporal declines in influenza activity varied among countries.