The European Centre for Disease Prevention and Control (ECDC) periodically publishes influenza characterisation reports, giving an overview of circulating influenza viruses. These reports provide details on current vaccine strains, summarise the development of viruses since the last report and closely follow the main developments for the ongoing influenza season.
On 21 April 2021, the ECDC published the fifth virus characterisation period report for the 2020 to 2021 influenza season. As of week 12 of 2021, 758 influenza detections across the World Health Organization (WHO) European Region had been reported, of which 50% were type A viruses, with A(H3N2) and A(H1N1)pdm09 being equally represented, and 50% were type B viruses, with 12 having been ascribed to a lineage, ten being B/Victoria and two B/Yamagata. These figures represent a 99.5% drop in detections compared with the same period in 2020.
Source: ECDC, 21 April 2021