tetano
Editor, Senior Moderator
Vaccine. 2017 Dec 14. pii: S0264-410X(17)31777-2. doi: 10.1016/j.vaccine.2017.12.024. [Epub ahead of print]
[h=1]An updated influenza A(H3N2) vaccine generates limited antibody responses to previously encountered antigens in children.[/h] Florek NW[SUP]1[/SUP], Campos LM[SUP]1[/SUP], Braun KM[SUP]1[/SUP], McLean HQ[SUP]2[/SUP], King JP[SUP]2[/SUP], Flannery B[SUP]3[/SUP], Belongia EA[SUP]4[/SUP], Friedrich TC[SUP]5[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Influenza vaccination may provide a "back-boost" to antibodies against previously encountered strains. If the back-boost effect is common, this could allow more aggressive vaccine updates, as emerging variants would be expected to both elicit de-novo responses and boost pre-existing responses against recently circulating strains. Here we used the emergence of an antigenically novel A(H3N2) strain to determine whether an antigenically updated vaccine boosted antibodies against historical strains.
[h=4]METHODS:[/h] We performed hemagglutination-inhibition (HI) assays on pre- and post-vaccination sera from 124 children 5-17 years old who received 2015-2016 inactivated influenza vaccine, containing an antigenically updated A(H3N2) strain. We evaluated the mean fold increase in HI titer against both the 2015-2016 vaccine strain and representative strains from two prior antigenic clusters. Factors associated with post-vaccination titers against historical strains were evaluated using linear regression, adjusting for baseline titer.
[h=4]RESULTS:[/h] Geometric mean titers against each antigen examined increased significantly after vaccination (P < .0001). Mean fold increase was 3.29 against the vaccine strain and 1.22-1.46 against historical strains. Response to vaccine strain was associated with increased post-vaccination titers against historical strains.
[h=4]CONCLUSIONS:[/h] A vaccine containing an antigenically novel A(H3N2) strain modestly boosted antibody responses against historical influenza strains in children.
Copyright ? 2017. Published by Elsevier Ltd.
[h=4]KEYWORDS:[/h] Back-boost; Influenza; Pediatrics; Vaccine
PMID: 29249543 DOI: 10.1016/j.vaccine.2017.12.024
[h=1]An updated influenza A(H3N2) vaccine generates limited antibody responses to previously encountered antigens in children.[/h] Florek NW[SUP]1[/SUP], Campos LM[SUP]1[/SUP], Braun KM[SUP]1[/SUP], McLean HQ[SUP]2[/SUP], King JP[SUP]2[/SUP], Flannery B[SUP]3[/SUP], Belongia EA[SUP]4[/SUP], Friedrich TC[SUP]5[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Influenza vaccination may provide a "back-boost" to antibodies against previously encountered strains. If the back-boost effect is common, this could allow more aggressive vaccine updates, as emerging variants would be expected to both elicit de-novo responses and boost pre-existing responses against recently circulating strains. Here we used the emergence of an antigenically novel A(H3N2) strain to determine whether an antigenically updated vaccine boosted antibodies against historical strains.
[h=4]METHODS:[/h] We performed hemagglutination-inhibition (HI) assays on pre- and post-vaccination sera from 124 children 5-17 years old who received 2015-2016 inactivated influenza vaccine, containing an antigenically updated A(H3N2) strain. We evaluated the mean fold increase in HI titer against both the 2015-2016 vaccine strain and representative strains from two prior antigenic clusters. Factors associated with post-vaccination titers against historical strains were evaluated using linear regression, adjusting for baseline titer.
[h=4]RESULTS:[/h] Geometric mean titers against each antigen examined increased significantly after vaccination (P < .0001). Mean fold increase was 3.29 against the vaccine strain and 1.22-1.46 against historical strains. Response to vaccine strain was associated with increased post-vaccination titers against historical strains.
[h=4]CONCLUSIONS:[/h] A vaccine containing an antigenically novel A(H3N2) strain modestly boosted antibody responses against historical influenza strains in children.
Copyright ? 2017. Published by Elsevier Ltd.
[h=4]KEYWORDS:[/h] Back-boost; Influenza; Pediatrics; Vaccine
PMID: 29249543 DOI: 10.1016/j.vaccine.2017.12.024