Antibody Persistence and Booster Responses to Split-Virion H5N1 Avian Influenza Vaccine in Young and Elderly Adults

PLoS One. 2016 Nov 4;11(11):e0165384. doi: 10.1371/journal.pone.0165384. eCollection 2016.

Abstract

Avian influenza continues to circulate and remains a global health threat not least because of the associated high mortality. In this study antibody persistence, booster vaccine response and cross-clade immune response between two influenza A(H5N1) vaccines were compared. Participants aged over 18-years who had previously been immunized with a clade 1, A/Vietnam vaccine were re-immunized at 6-months with 7.5 μg of the homologous strain or at 22-months with a clade 2, alum-adjuvanted, A/Indonesia vaccine. Blood sampled at 6, 15 and 22-months after the primary course was used to assess antibody persistence. Antibody concentrations 6-months after primary immunisation with either A/Vietnam vaccine 30 μg alum-adjuvanted vaccine or 7.5 μg dose vaccine were lower than 21-days after the primary course and waned further with time. Re-immunization with the clade 2, 30 μg alum-adjuvanted vaccine confirmed cross-clade reactogenicity. Antibody cross-reactivity between A(H5N1) clades suggests that in principle a prime-boost vaccination strategy may provide both early protection at the start of a pandemic and improved antibody responses to specific vaccination once available.

Trial registration: ClinicalTrials.gov NCT00415129.

Publication types

  • Clinical Trial, Phase II

MeSH terms

  • Adjuvants, Immunologic / administration & dosage
  • Adolescent
  • Adult
  • Animals
  • Antibodies, Viral / immunology*
  • Antibody Formation / immunology
  • Birds / immunology
  • Birds / virology
  • Humans
  • Immunization, Secondary / methods
  • Indonesia
  • Influenza A Virus, H5N1 Subtype / immunology*
  • Influenza Vaccines / immunology*
  • Influenza in Birds / immunology*
  • Influenza in Birds / virology
  • Influenza, Human / immunology*
  • Influenza, Human / virology
  • Male
  • Middle Aged
  • Neutralization Tests / methods
  • Vaccination / methods
  • Vietnam
  • Virion / immunology*
  • Young Adult

Substances

  • Adjuvants, Immunologic
  • Antibodies, Viral
  • Influenza Vaccines

Associated data

  • ClinicalTrials.gov/NCT00415129

Grants and funding

The funder provided support in the form of salary for one author [SP]. The funder contributed to study design, monitoring of data collection, statistical analysis and review of manuscript. The data analysis was reviewed by an independent statistician (MV) and the decision to publish was led by the other authors (AJP, PVD, GLR). The manuscript was prepared by RL and reviewed by all other authors.