title: Influenza Β/Victoria antigen induces strong recall of Β/Yamagata but lower Β/Victoria response in children primed with two doses of Β/Yamagata.
abstract: OBJECTIVE
  Trivalent inactivated influenza vaccine (TIV) contains 1 of 2 influenza B/lineages (B/Yamagata or B/Victoria) annually. We assessed prime-boost responses in young children following a change in the B/lineage included in TIV.
  
  
  METHODS
  Participants were primed during a clinical trial as infants or toddlers with two 0.25 or two 0.5 mL doses of 2008-2009 TIV containing B/Florida/4/06(Yamagata) antigen. In subsequent years, sequential subsets received annual age-appropriate doses of 2009-2010 and 2010-2011 TIV containing the changed influenza B/lineage antigen (B/Brisbane/60/08(Victoria)). Serologic response was assessed pre- and postimmunization by hemagglutination inhibition (HI; with/without ether treatment of influenza B antigen) and microneutralization. The primary immunogenicity outcome was the seroprotection rate (SPR) measured by HI without ether treatment (SPR:HI titers ≥40).
  
  
  RESULTS
  Fifty-six children were included in 2009-2010 and 36 in 2010-2011 analyses. Before the 2009-2010 TIV dose, antibody to all 2008-2009 TIV components had fallen to low levels: SPR <10% for B/Florida/4/06(Yamagata) and B/Brisbane/60/08(Victoria) antigens. A single 2009-2010 TIV dose boosted antibody to the shared 2008-2009/2009-2010 influenza A antigens and to the priming 2008-2009 B/Florida/4/06(Yamagata) antigen with SPRs >85%. In contrast, antibody to the B/Brisbane/60/08(Victoria) antigen included in the 2009-2010 TIV remained low: SPR <25%. Antibody to the B/Brisbane/60/08(Victoria) antigen was not improved from a further dose in the 2010-2011 TIV: SPR 31% versus SPR 69% to B/Yamagata. A similar pattern of B/Yamagata dominance was observed when HI testing was conducted with antigen prepared by ether treatment.
  
  
  CONCLUSIONS
  Repeated annual TIV doses containing B/Victoria-lineage antigen strongly recalled antibodies to the B/Yamagata antigen of first exposure, but elicited lower B/Victoria responses.
authors.affiliation: British Columbia Centre for Disease Control, Vancouver, British Columbia, Canada. danuta.skowronski@bccdc.ca
authors.forename: Danuta M
authors.initials: DM
authors.lastname: Skowronski
authors.forename: Travis S
authors.initials: TS
authors.lastname: Hottes
authors.forename: Gaston
authors.initials: G
authors.lastname: De Serres
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Ward
authors.forename: Naveed Z
authors.initials: NZ
authors.lastname: Janjua
authors.forename: Suzana
authors.initials: S
authors.lastname: Sabaiduc
authors.forename: Tracy
authors.initials: T
authors.lastname: Chan
authors.forename: Martin
authors.initials: M
authors.lastname: Petric
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000276:immunology*; D006385:Hemagglutination Inhibition Tests; D006389:Hemagglutinins, Viral / Q000235:genetics; D006801:Humans; D007117:Immunization, Secondary / Q000379:methods; D007156:Immunologic Memory; D007223:Infant; D009981:Influenza B virus / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D014611:Vaccination / Q000379:methods; D015164:Vaccines, Inactivated / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D006389:Hemagglutinins, Viral; D007252:Influenza Vaccines; D012367:RNA, Viral; D015164:Vaccines, Inactivated; C458881:hemagglutinin fusogenic peptide, influenza virus