title: Heterovariant cross-reactive B-cell responses induced by the 2009 pandemic influenza virus A subtype H1N1 vaccine.
abstract: BACKGROUND
  The generation of heterovariant immunity is a highly desirable feature of influenza vaccines. The goal of this study was to compare the heterovariant B-cell response induced by the monovalent inactivated 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09) vaccine with that induced by the 2009 seasonal trivalent influenza vaccine (sTIV) containing a seasonal influenza A virus subtype H1N1 (A[H1N1]) component in young and elderly adults.
  
  
  METHODS
  Plasmablast-derived polyclonal antibodies (PPAb) from young and elderly recipients of A(H1N1)pdm09 vaccine or sTIV were tested for binding activity to various influenza antigens.
  
  
  RESULTS
  In A(H1N1)pdm09 recipients, the PPAb titers against homotypic A(H1N1)pdm09 vaccine were similar to those against the heterovariant seasonal A(H1N1) vaccine and were similar between young and elderly subjects. The PPAb avidity was higher among elderly individuals, compared with young individuals. In contrast, the young sTIV recipients had 10-fold lower heterovariant PPAb titers against the A(H1N1)pdm09 vaccine than against the homotypic seasonal A(H1N1) vaccine. In binding assays with recombinant head and stalk domains of hemagglutinin, PPAb from the A(H1N1)pdm09 recipients but not PPAb from the sTIV recipients bound to the conserved stalk domain.
  
  
  CONCLUSIONS
  The A(H1N1)pdm09 vaccine induced production of PPAb with heterovariant reactivity, including antibodies targeting the conserved hemagglutinin stalk domain.
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, USA. xiaosong@stanford.edu
authors.forename: Xiao-Song
authors.initials: XS
authors.lastname: He
authors.forename: Sanae
authors.initials: S
authors.lastname: Sasaki
authors.forename: Jane
authors.initials: J
authors.lastname: Baer
authors.forename: Surender
authors.initials: S
authors.lastname: Khurana
authors.forename: Hana
authors.initials: H
authors.lastname: Golding
authors.forename: John J
authors.initials: JJ
authors.lastname: Treanor
authors.forename: David J
authors.initials: DJ
authors.lastname: Topham
authors.forename: Mark Y
authors.initials: MY
authors.lastname: Sangster
authors.forename: Hong
authors.initials: H
authors.lastname: Jin
authors.forename: Cornelia L
authors.initials: CL
authors.lastname: Dekker
authors.forename: Kanta
authors.initials: K
authors.lastname: Subbarao
authors.forename: Harry B
authors.initials: HB
authors.lastname: Greenberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D001402:B-Lymphocytes / Q000276:immunology*; D003429:Cross Reactions; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology / Q000821:virology; D008297:Male; D058873:Pandemics; D012621:Seasons; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines