title: [Virological characterization of influenza A(H3N2) virus in Mainland China during 2011-2012].
abstract: To study the prevalence and variation of influenza A(H3N2) viruses, the antigenic and genetic characteristics of influenza A(H3N2) viruses circulating in Mainland China during April 2011 to March 2012 were analyzed. The results showed that influenza A(H3N2) viruses increased gradually since 2012 and became the dominant strain since March. The viruses were antigenically closely related to the vaccine strain A/PER/16/09 (87.2%) and the representative virus A/FJ/196/09 (76.0%) in Mainland China. The genetic characteristics analysis results showed that recently isolated viruses belonged to the Vic/208 clade, and most of the low reaction strains also fell into the same clade. Crystal structure analysis of HA protein found that, compared with the vaccine strain A/PER/16/09, the recently isolated viruses had amino acid substitutions in the antigenic site A, B and C areas, in addition to gaining potential glycosylation sites at the amino acid position of 45 of HA and 367 of NA. Although the majority of circulating influenza A (H3N2) viruses in 2011-2012 season in Mainland China were antigeniclly matched by current influenza vaccine strain and the selected representative viruses, low reaction strains have increased since 2012, therefore it is necessary to strengthen the surveillance on the variation of influenza virus and to provide solid information for the vaccine strain selection.
authors.affiliation: Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, China CDC, WHO Collaborating Center for Reference and Research on Influenza, Beijing 102206, China. huangweijuan@cnic.org.cn
authors.forename: Wei-Juan
authors.initials: WJ
authors.lastname: Huang
authors.forename: Yan-Hui
authors.initials: YH
authors.lastname: Cheng
authors.forename: Xi-Yan
authors.initials: XY
authors.lastname: Li
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhao
authors.forename: Jun-Feng
authors.initials: JF
authors.lastname: Guo
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wang
authors.forename: Min-Ju
authors.initials: MJ
authors.lastname: Tan
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Sui
authors.forename: He-Jiang
authors.initials: HJ
authors.lastname: Wei
authors.forename: Yao-Yao
authors.initials: YY
authors.lastname: Chen
authors.forename: Ning
authors.initials: N
authors.lastname: Xiao
authors.forename: Yu
authors.initials: Y
authors.lastname: Lan
authors.forename: Da-Yan
authors.initials: DY
authors.lastname: Wang
authors.forename: Yue-Long
authors.initials: YL
authors.lastname: Shu
mesh_terms: D000595:Amino Acid Sequence; D002681:China / Q000453:epidemiology; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000235:genetics; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus