Safety and Immunogenicity of an MF59(®)-adjuvanted A/H5N1 Pre-Pandemic Influenza Vaccine in Adults and the Elderly

Vaccine. 2012 Feb 8;30(7):1388-96. doi: 10.1016/j.vaccine.2011.12.009. Epub 2011 Dec 20.

Abstract

Background: The potential consequences of an avian influenza pandemic warrants the development of safe, highly immunogenic pre-pandemic A/H5N1 vaccines with cross-clade protection. In this randomized, controlled study we compared the immunogenicity and safety of an MF59(®)-adjuvanted (Novartis Vaccines, Marburg, Germany) A/H5N1 pre-pandemic vaccine with that of a licensed, MF59-adjuvanted, seasonal influenza vaccine.

Methods: Healthy adult (18-60 years, n=3372) and elderly (≥61 years, n=275) volunteers received either an initial dose of a licensed, non-adjuvanted, trivalent, seasonal influenza vaccine (Agrippal(®)) on Day 1, followed by one dose of MF59-H5N1 study vaccine on Day 22 and a second dose of MF59-H5N1 on Day 43, or alternatively, placebo on Day 1 followed by one dose of MF59-adjuvanted seasonal reference vaccine on Day 22 and a second dose of reference vaccine on Day 43. Homologous and cross-reactive A/H5N1 antibody responses were analysed by haemagglutination inhibition (HI), single radial haemolysis (SRH), and microneutralization (MN) assays three weeks after each vaccination. Vaccine safety was assessed throughout the study.

Results: Analysis by HI assay found that two doses of MF59-H5N1 resulted in a seroconversion rate of 56% and a geometric mean ratio (GMR) of 7.1 in adult subjects. Similar results were observed on analysis by SRH (GMR 4.03; seroconversion 78% and seroprotection 91%) and MN (seroconversion 67%) assays. These data met the European licensure criteria for influenza vaccines. No significant difference in immunogenicity was detected between the adult and elderly populations. Anti-A/H5N1 cross-clade antibodies were detected by SRH, 49% of adult and 32% of elderly subjects achieved seroconversion after the second vaccine dose. Overall, MF59-H5N1 containing 7.5μg antigen was less reactogenic than the MF59-adjuvanted trivalent seasonal vaccine which contained 15μg antigen for each component strain.

Conclusions: Two doses of MF59-H5N1 vaccine were well tolerated and induced adequate levels of seroprotection against homologous and cross-clade A/H5N1 virus. These data support the suitability of MF59-adjuvanted A/H5N1 vaccine for pre-pandemic use in adults and the elderly.

Trial registration: ClinicalTrials.gov NCT00841763.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Viral / biosynthesis
  • Antibodies, Viral / immunology
  • Cross Protection
  • Drug Administration Schedule
  • Female
  • Hemagglutination Inhibition Tests
  • Humans
  • Influenza A Virus, H5N1 Subtype / immunology*
  • Influenza Vaccines / immunology*
  • Influenza, Human / immunology
  • Influenza, Human / prevention & control*
  • Influenza, Human / virology
  • Male
  • Middle Aged
  • Pandemics / prevention & control*
  • Vaccination*
  • Young Adult

Substances

  • Adjuvants, Immunologic
  • Antibodies, Viral
  • Influenza Vaccines

Associated data

  • ClinicalTrials.gov/NCT00841763