title: Challenges in antigenic characterization of circulating influenza A(H3N2) viruses during the 2011-2012 influenza season: an ongoing problem?
abstract: Genetic and antigenic characterization of 37 representative influenza A(H3N2) virus strains isolated in Greece during the 2011-2012 winter season was performed to evaluate matching of the viruses with the seasonal influenza vaccine strain A/Perth/16/2009. Hemagglutinin gene sequence analysis revealed that all Greek strains clustered within the Victoria/208 genetic clade. Furthermore, substitutions in the antigenic and glycosylation sites suggested potential antigenic drift. Our hemagglutination inhibition (HI) analysis showed that the Greek viruses were Perth/16-like; however, these viruses were characterized as Victoria/208-like when tested at the United Kingdom WHO Collaborating Centre (CC) with HI assays performed in the presence of oseltamivir, a finding consistent with the genetic characterization data. Variability in the HI test performance experienced by other European laboratories indicated that antigenic analysis of the A(H3N2) virus has limitations and, until its standardization, national influenza reference laboratories should include genetic characterization results for selection of representative viruses for detailed antigenic analysis by the WHO CCs.
authors.affiliation: National Influenza Reference Laboratory for Southern Greece, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Kossyvakis
authors.affiliation: National Influenza Reference Laboratory for Southern Greece, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Pogka
authors.affiliation: National Influenza Reference Laboratory for Northern Greece, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Aggeliki
authors.initials: A
authors.lastname: Melidou
authors.affiliation: National Influenza Reference Laboratory for Southern Greece, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Afroditi
authors.initials: A
authors.lastname: Moutousi
authors.affiliation: National Influenza Reference Laboratory for Northern Greece, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Gioula
authors.affiliation: National Influenza Reference Laboratory for Southern Greece, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Antonios
authors.initials: A
authors.lastname: Kalliaropoulos
authors.affiliation: National Influenza Reference Laboratory for Northern Greece, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Exindari
authors.affiliation: National Influenza Reference Laboratory for Southern Greece, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Mary
authors.initials: M
authors.lastname: Emmanouil
authors.affiliation: National Influenza Reference Laboratory for Southern Greece, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Elina
authors.initials: E
authors.lastname: Horefti
authors.affiliation: Department of Epidemiological Surveillance and Intervention, Hellenic Centre for Disease Control and Prevention, Athens, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Spala
authors.affiliation: National Institute for Public Health and the Environment, Centre for Infectious Disease Control, Bilthoven, Netherlands.
authors.forename: Adam
authors.initials: A
authors.lastname: Meijer
authors.affiliation: National Influenza Reference Laboratory for Northern Greece, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Malisiovas
authors.affiliation: National Influenza Reference Laboratory for Southern Greece, Hellenic Pasteur Institute, Athens, Greece mentis@pasteur.gr.
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Mentis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000956:Antigens, Viral / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D005260:Female; D005838:Genotype; D006115:Greece; D006385:Hemagglutination Inhibition Tests; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053122:Influenza A Virus, H3N2 Subtype / Q000737:chemistry* / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D000956:Antigens, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus