|TUMPEY, TERRY - Centers For Disease Control And Prevention (CDCP) - United States|
|PUSHKO, PETER - Medigen, Inc|
Submitted to: World Veterinary Poultry Association
Publication Type: Abstract Only
Publication Acceptance Date: 5/18/2015
Publication Date: N/A
Technical Abstract: Avian influenza (AI) viruses, especially H5 subtypes, cause widespread morbidity and mortality in domestic and wild bird populations. Dissemination of AI results primarily from the movement of the virus through infected poultry and poultry products, but migratory birds have also served as secondary vectors for the virus, rapidly spreading HPAI to Asia, Europe, U.S., and Africa. Vaccine development for avian influenza is challenging because of frequent, unpredictable changes in viral structure via antigenic drift and antigenic shift. Because of the genetic drift, influenza viruses accumulate mutations and continuously change. Therefore, influenza vaccines also need to be changed to match circulating virus strains. Several approaches are being tested that allow induction of immunity to conserved viral protein regions, including the hemagglutinin (HA). Previously, we have developed recombinant virus-like particles (VLPs) as a promising influenza vaccine. The VLPs have been shown to provide broader protection as compared to conventional whole virus or subunit vaccines. The long-term goal of this research is to develop multivalent AI vaccines that can be administered to commercial bird flocks via respiratory tract and protect against multiple strains of AI. In these studies, both types of multi-HA VLPs (multi-subtype and multi-clade) were manufactured in Sf9 cells and immunogenicity and efficacy evaluated in specific pathogen-free (SPF) chickens following subcutaneous vaccine administration and intranasal challenges from highly pathogenic H5 AI. Protection and efficacy following challenge will be discussed.