Influenza virus identified in European Union nations
Throughout the 2014 and 2015 influenza season, two viruses called influenza A (H3N2), A(H1N1)pdm09 and type B viruses began to co-circulate throughout countries in the E.U. and European Economic Area (EEA). As of today, 28 different E.U./EEA nations have shared over 1,000 samples of influenza-positive specimens with the Collaborating Centre in London of the World Health Organization.
The goal in gathering these samples of specimens is to create a detailed characterization of the viruses.
The characterization process began in July 2015, when researchers wrote a report involving 102 viruses antigenically and an additional 60 viruses genetically. Now another 30 A(H1N1)pdm09 viruses have been antigenically characterized as being similar to the vaccine virus A/California/07/2009. All of the 26 samples that have been characterized genetically showed HA genes similar to the genetic subgroup 6B.
An additional 24 A(H3N2) test viruses have been characterized by their haemagglutination inhibition (HI) assay. They were poorly recognized, with titres approximately fourfold reduced when compared to homologous titre. The researchers used antiserum from A/Texas/50/2012 as a reference to find the vaccine virus recommended during the 2014-2015 northern hemisphere influenza season.
Further details are available on the European Centres for Disease Control and Prevention website.