ARS | Publication request: Vaccination of SPF turkeys with a recombinant HVT expressing the HA from H5N1 highly pathogenic avian influenza protects against lethal challenge

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 7, 2012
Publication Date: August 4, 2012
Citation: Kapczynski, D.R., Moraes, M., Jackwood, M.W., Dorsey, K.M. 2012. Vaccination of SPF turkeys with a recombinant HVT expressing the HA from H5N1 highly pathogenic avian influenza protects against lethal challenge [abstract]. American Association of Avian Pathologists Annual meeting. CDROM.

Technical Abstract: Vaccination is an important tool in the protection of poultry against avian influenza (AI). For field use, the overwhelming majority of AI vaccines produced are inactivated whole virus formulated into an oil emulsion and to a lesser degree recombinant vectored vaccines (e.g. virus expressing AI genes). The objective of this study was to evaluate the efficacy of the recombinant Vectormune HVT-AI (rHVT-AI) against challenge with highly pathogenic (HP) strain of H5N1 avian influenza virus (AIV) in specific pathogen free (SPF) turkeys. Furthermore, a group vaccinated with a combination of rHVT-AI and an inactivated AIV vaccine was included to evaluate synergism between these vaccines. Most all birds (98 %) receiving the rHVT AI were protected from clinical signs of disease and mortality. In contrast, all sham-vaccinated birds died by day 4 post-challenge. In addition, oral and cloacal swabs taken from challenged birds demonstrated that vaccinated birds had lower incidence and titers of viral shedding compared to sham-vaccinated birds. Taken together, these studies provide support for the use of rHVT vaccines expressing HA to protect poultry against HPAI challenge.