Comparison of human H3N2 antibody responses elicited by egg-based, cell-based, and recombinant protein-based influenza vaccines during the 2017-2018 season.


These data suggest that influenza vaccine antigen match and dose are both important for eliciting optimal H3N2 antibody responses in humans. Future studies should be designed to determine if our findings directly impact vaccine effectiveness.

We compared antibody responses in humans vaccinated with Fluzone (egg-based, n=23), Fluzone High-Dose (egg-based, n=16), Flublok (recombinant protein-based, n=23), or Flucelvax (cell-based, n=23) during the 2017-2018 season. We completed neutralization assays using an egg-adapted H3N2 virus, a cell-based H3N2 virus, wild-type 3c2.A and 3c2.A2 H3N2 viruses, and the H1N1 vaccine strain. We also performed ELISAs using a recombinant wild-type 3c2.A HA. Antibody responses were compared in adjusted analysis.

The H3N2 component of egg-based 2017-2018 influenza vaccines possessed an adaptive substitution that alters antigenicity. Several influenza vaccines include antigens that are produced through alternative systems, but a systematic comparison of different vaccines used during the 2017-2018 has not been completed.

Post-vaccination neutralizing antibody titers to 3c2.A and 3c2.A2 were higher in Flublok recipients compared to Flucelvax or Fluzone recipients (p<0.01). Post-vaccination titers to 3c2.A and 3c2.A2 were similar in Flublok and Fluzone High-Dose recipients, though seroconversion rates trended higher in Flublok recipients. Post-vaccination titers in Flucelvax recipients were low to all H3N2 viruses tested, including the cell-based H3N2 strain. Post-vaccination neutralizing antibody titers to H1N1 were similar among the different vaccine groups.

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