摘要：As part of its role in the World Health Organization’s(WHO) Global Influenza Surveillance andResponse System, the WHO CollaboratingCentre for Reference and Research on Influenzain Melbourne received a total of 5,557 influenzapositive samples during 2015. Viruses wereanalysed for their antigenic, genetic and antiviralsusceptibility properties. In 2015, influenza Bviruses predominated over influenza A(H1)pdm09and A(H3) viruses, accounting for a total of 58%of all viruses analysed. The vast majority of A(H1)pdm09, A(H3) and influenza B viruses analysed atthe Centre were found to be antigenically similarto the respective WHO recommended vaccinestrains for the Southern Hemisphere in 2015.However, phylogenetic analysis of a selection ofviruses indicated that the majority of circulatingA(H3) viruses were genetically distinct from theWHO recommended strain for 2015, resultingin an update to the recommended vaccine strainfor the Southern Hemisphere for 2016. With anincreasing predominance of B/Victoria lineageviruses over B/Yamagata lineage viruses throughthe course of 2015, WHO also updated therecommended influenza B strain in the trivalentinfluenza vaccine for 2016. Of more than 3,300samples tested for resistance to the neuraminidaseinhibitors oseltamivir and zanamivir, only 1 A(H1)pdm09 virus showed highly reduced inhibitionby oseltamivir. The Centre undertook primaryisolation of candidate vaccine viruses directlyinto eggs, and in 2015 a total of 45 viruses weresuccessfully isolated in eggs.
