Ladman BS, et al. Protection Afforded By Avian Influenza Vaccination Programs Consisting Of A Novel RNA Particle And An Inactivated Avian Influenza Vaccine Against A Highly Pathogenic Avian Influenza Virus Challenge In. Avian Pathol. 2019 Apr 9:1-34
The efficacies of an oil adjuvanted-inactivated reverse genetics derived H5 avian influenza virus (AIV) vaccine and an alphavirus replicon RNA particle (RP) AIV vaccine were evaluated in commercial leghorn chickens. Challenge utilized A/Turkey/MN/12582/2015, an isolate representing the U.S. H5N2 Clade 188.8.131.52 responsible for the 2015 highly pathogenic avian influenza (HPAI) epornitic in commercial poultry the United States. As part of long term, 36-week study, chickens were challenged at seven weeks of age after receiving a single vaccination, at 18 weeks of age after following a vaccine prime-single boost and at 36 weeks of age after a prime- double-boost. All vaccine programs reduced virus oropharyngeal and cloacal shedding and mortality compared to the non-vaccinated control birds however, chickens receiving at least one administration of the RP vaccine generally had diminished viral shed especially from the cloacal swabbings. A detectable serum antibody response and protection was observed through 18 weeks post vaccination. Our data suggest that in conjunction with a comprehensive eradication, enhanced biosecurity and controlled marketing plan, vaccination programs of commercial layer chickens with novel RP vaccines may represent an important tool for preventing HPAI related mortalities and decreasing viral load during a catastrophic influenza outbreak. Research Highlights Immunization of poultry following a vaccination schedule consisting of inactivated and RNA particle vaccines offered significant protection against lethal disease following HPAIV challenge. Virus shedding was significantly (p?0.05) reduced in chickens vaccinated with either inactivated and/or recombinant vaccines. Serum antibody titers were not a reliable indicator of protection. An inactivated vaccine containing 384 HAU of the homologous antigen was unable to induce complete protection.
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