Homologous and heterologous antigenic matched vaccines containing different H5 hemagglutinins provide variable protection of chickens from the 2014 U.S. H5N8 and H5N2 clade 2.3.4.4 highly pathogenic avian influenza viruses.

摘要: From December 2014 to June 2015, a novel H5 Eurasian A/goose/Guangdong (Gs/GD) lineage clade 2.3.4.4 high pathogenicity avian influenza (HPAI) virus caused the largest animal health emergency in US history resulting mortality or culling of greater than 48 million poultry. The outbreak renewed interest developing intervention strategies, including vaccines, for these newly emergent HPAI viruses. In studies, several existing vaccines vaccine seed strains with varying genetic relatedness (85-100%) viruses were evaluated protection Chickens received single dose either an inactivated whole AI vaccine, recombinant fowl poxvirus turkey herpesvirus-vectored hemagglutinin gene inserts followed by challenge U.S. wild bird H5N8 (A/gyrfalcon/Washington/40188-6/2014) H5N2 (A/northern pintail/Washington/40964/2014) isolate. Results indicate that most provided 100% from lethal effects challenge. contrast, live vectored only partial which ranged 40 70%. Inactivated groups, general, had lower number birds shedding and at titers then groups. Interestingly, prechallenge antibody using as antigen heterologous groups typically low (≤2 log2), yet majority survived Taken together, studies suggest when used immunization strategy may not provide adequate poultry against Updating be genetically closer and/or prime-boost necessary optimal protection.