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 16 November 2021, the ECDC published the first virus characterisation period report for the 2021 to 2022 influenza season. As of week 44 of 2021, 965 influenza detections across the World Health Organization (WHO) European Region had been reported. Of these, 86% were type A viruses, with A(H3N2) dominating over A(H1N1)pdm09, and 14% were type B viruses, with none having being ascribed a lineage. This represents an increase in detections compared to the 2020 to 2021 season, following a large increase in the number of samples tested, and is close to the more usual number of detections seen in earlier influenza seasons.
Source: ECDC, 16 November 2021