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133rd Annual Meeting & Exposition December 10-14, 2005 Philadelphia, PA |
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Adam Soloff, Graduate School of Public Health, University of Pittsburgh, 130 Desoto Street, 724 Parran Hall, Pittsburgh, PA 15261, 412-855-6367, ccrimmins@asph.org
Background: The ability of highly pathogenic avian influenza strain H5N1 to be transmitted between humans with an associated seventy-five percent mortality rate is raising concerns over the potential for an influenza pandemic. Conventional vaccination methods fail to account for such lethal strains, and require prohibitively long preparation times limiting their utility in outbreak containment.
Study Design: Adenoviral-based vaccines targeting regions of the H5N1 surface protein hemagglutinin(HA) were developed in 36 days based on sequences from the 1997 Hong Kong or 2004 Vietnam outbreaks. Four groups of mice received prime-boost immunization regimens targeting either full or partial length Vietnam HA, partial length Hong Kong HA, or mock vaccination. 16 weeks following the final immunization, animals were challenged with a lethal dose of the H5N1 Vietnam virus.
Results: Although all animals rapidly developed HA-specific antibody titers post-immunization, only mice receiving the full-length Vietnam HA vaccine developed antibody responses capable of neutralizing heterologous virus. In contrast, vaccination induced broad and potent cellular immunity in all animals regardless of viral strain or HA region immunized against. Characterization of vaccine induced cellular immune responses identified cross-reactive epitopes conserved within both Vietnam and Hong Kong viruses targeted by all immunizations. In addition, strain specific epitopes were isolated in non-conserved regions between the viral strains. Upon viral challenge, control animals died within nine days, whereas all vaccinated animals survived showing minimal transient weight loss.
Conclusions: These findings illustrate the potential efficacy of adenoviral-based vaccination in containing influenza outbreaks through the rapid induction of cellular and humoral immunity.
Learning Objectives:
Keywords: Infectious Diseases, Immunizations
Presenting author's disclosure statement:
I wish to disclose that I have NO financial interests or other relationship with the manufactures of commercial products, suppliers of commercial services or commercial supporters.
The 133rd Annual Meeting & Exposition (December 10-14, 2005) of APHA