OBJECTIVES: 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.
OBJECTIVES: 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: Cuiling Xu; Kwok-Hung Chan; Tim K Tsang; Vicky J Fang; Rita O P Fung; Dennis K M Ip; Simon Cauchemez; Gabriel M Leung; J S Malik Peiris; Benjamin J Cowling Journal: Am J Epidemiol Date: 2015-09-22 Impact factor: 4.897
Authors: Danuta M Skowronski; Marie-Eve Hamelin; Naveed Z Janjua; Gaston De Serres; Jennifer L Gardy; Chantal Rhéaume; Xavier Bouhy; Guy Boivin Journal: PLoS One Date: 2012-06-22 Impact factor: 3.240