Location: Exotic & Emerging Avian Viral Diseases Research
Title: Evaluation of Three Vaccine Technologies to Protect White leghorn Chickens from H5N2 clade 2.3.4.4 Gs/GD High Pathogenicity Avian InfluenzaAuthor
BERTRAN, KATERI - Consultant | |
Balzli, Charles | |
LEE, DONG-HUN - Orise Fellow | |
Suarez, David | |
Kapczynski, Darrell | |
Swayne, David |
Submitted to: World Veterinary Poultry Association
Publication Type: Abstract Only Publication Acceptance Date: 3/1/2017 Publication Date: 3/1/2017 Citation: Bertran, K., Balzli, C.L., Lee, D., Suarez, D.L., Kapczynski, D.R., Swayne, D.E. 2017. Evaluation of Three Vaccine Technologies to Protect White leghorn Chickens from H5N2 clade 2.3.4.4 Gs/GD High Pathogenicity Avian Influenza. Abstract book of World Veterinary Poultry Association xxth Congress 2017, Edingburgh, Scotland, September 4-8, 2017. Paper No. 297. Interpretive Summary: Technical Abstract: During December 2014-June 2015, the USA experienced a high pathogenicity avian influenza (HPAI) outbreak caused by clade 2.3.4.4 H5Nx Goose/Guangdong lineage viruses which was the worst HPAI event for the USA’s poultry industries. Three emergency vaccines, based on updating existing registered vaccines or licensed technologies, were developed for potential future use. In this study we assessed the efficacy of a reverse genetic avian influenza inactivated vaccine (rgH5N1), a recombinant herpesvirus turkey vectored vaccine (rHVT-H5), and an RNA particle (RP-H5) vaccine in White Leghorn chickens against clade 2.3.4.4 H5N2 HPAI virus challenge. In Study 1, single (rHVT-H5) and prime-boost (rHVT-H5 + rgH5N1 or rHVT-H5 + RP-H5) vaccination strategies protected 3-week-old chickens with high levels of protective immunity and significantly reduced virus shedding. In Study 2, single vaccination with either rgH5N1 or RP-H5 vaccines provided clinical protection in adult chickens and significantly reduced virus shedding. In Study 3, double rgH5N1 vaccination protected adult chickens from clinical signs and mortality when challenged 20 weeks post-boost, with high levels of long-lasting protective immunity and significantly reduced virus shedding. These studies support the use of genetically related vaccines for emergency vaccination programs against clade 2.3.4.4 H5Nx HPAI virus in young and adult layers. |