Virological surveillance of influenza viruses in the WHO European Region in 2019/20 – impact of the COVID-19 pandemic
Angeliki Melidou, Dmitriy Pereyaslov, Olav Hungnes, Katarina Prosenc, Erik Alm, Cornelia Adlhoch, James Fielding, Miriam Sneiderman, Oksana Martinuka, Lucia Pastore Celentano, Richard Pebody, WHO European Region influenza surveillance network
Abstract
The COVID-19 pandemic negatively impacted the 2019/20 WHO European Region influenza surveillance. Compared with previous 4-year averages, antigenic and genetic characterisations decreased by 17% (3,140 vs 2,601) and 24% (4,474 vs 3,403). Of subtyped influenza A viruses, 56% (26,477/47,357) were A(H1)pdm09, 44% (20,880/47,357) A(H3). Of characterised B viruses, 98% (4,585/4,679) were B/Victoria. Considerable numbers of viruses antigenically differed from northern hemisphere vaccine components. In 2020/21, maintaining influenza virological surveillance, while supporting SARS-CoV-2 surveillance is crucial.