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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 4/21/2014 Publication Date: 5/21/2014 Citation: Kapczynski, D.R. 2014. Immunogenicity of avian influenza H7N9 virus in birds: Identification of viral epitopes recognized by the immune system following vaccination and challenge [abstract}. Internet Webinar. Available: www.pepperprint.com. Interpretive Summary: Technical Abstract: In March of 2013, the first cases of H7N9 influenza were reported in humans in China and shortly thereafter the virus was isolated from poultry in live bird markets. In 2014, a second wave of human infections occurred with similar mortality rates. The genetic composition of these H7N9 influenza viruses appears to be solely of avian origin, albeit of low pathogenicity in poultry. Although few isolations of these avian influenza (AI) viruses have been demonstrated on poultry farms, the correlation between live bird market shut downs and reduced human infections in China underscores a linkage between poultry and humans. In response to the outbreak, vaccine efficacy trials were recently performed to determine if inactivated H7N9 vaccine could increase resistance of birds to clinical disease and shedding of virus. A homologous H7N9 vaccine was formulated into an inactivated emulsion and injected at various doses into 3 week old SPF birds. Birds were challenged at 6 weeks of age with 108 EID50 per bird delivered via intranasal route. Sham vaccinated birds demonstrated 10 % mortality and reduction in weight gain. In contrast vaccinated groups demonstrated improved weight gain compared to sham vaccinated birds. Specific regions of the virus that induce antibodies were discovered following protein analysis. Taken together, these results indicate that the homologous vaccine can provide protection to poultry against this recent H7N9 virus and identified specific AI sequences recognized by the chicken immune system. |
