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Vaccine. 2017 Dec 14. pii: S0264-410X(17)31777-2. doi: 10.1016/j.vaccine.2017.12.024. [Epub ahead of print]
An updated influenza A(H3N2) vaccine generates limited antibody responses to previously encountered antigens in children.
Florek NW1, Campos LM1, Braun KM1, McLean HQ2, King JP2, Flannery B3, Belongia EA4, Friedrich TC5.
Author information
Abstract
BACKGROUND:
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.
METHODS:
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.
RESULTS:
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.
CONCLUSIONS:
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.
KEYWORDS:
Back-boost; Influenza; Pediatrics; Vaccine
PMID: 29249543 DOI: 10.1016/j.vaccine.2017.12.024
An updated influenza A(H3N2) vaccine generates limited antibody responses to previously encountered antigens in children.
Florek NW1, Campos LM1, Braun KM1, McLean HQ2, King JP2, Flannery B3, Belongia EA4, Friedrich TC5.
Author information
Abstract
BACKGROUND:
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.
METHODS:
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.
RESULTS:
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.
CONCLUSIONS:
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.
KEYWORDS:
Back-boost; Influenza; Pediatrics; Vaccine
PMID: 29249543 DOI: 10.1016/j.vaccine.2017.12.024