Mapping of H3n2 influenza antigenic evolutionin China reveals a strategy for vaccine strainrecommendation

摘要

One of the primary efforts in influenza vaccine strain recommendation is to monitor through genesequencing the viral surface protein haemagglutinin (HA) variants that lead to viral antigenicchanges. Here we have developed a computational method, denoted as PREDAC, to predictantigenic clusters of influenza A (H3n2) viruses with high accuracy from viral HA sequences.Application of PREDAC to large-scale HA sequence data of H3n2 viruses isolated from diverseregions of mainland China identified 17 antigenic clusters that have dominated for at least oneseason between 1968 and 2010. By tracking the dynamics of the dominant antigenic clusters,we not only find that dominant antigenic clusters change more frequently in China than in theunited states/Europe, but also characterize the antigenic patterns of seasonal H3n2 viruseswithin China. Furthermore, we demonstrate that the coupling of large-scale HA sequencingwith PREDAC can significantly improve vaccine strain recommendation for China.