title: Avian influenza mucosal vaccination in chickens with replication-defective recombinant adenovirus vaccine.
abstract: We evaluated protection conferred by mucosal vaccination with replication-competent adenovirus-free recombinant adenovirus expressing a codon-optimized avian influenza (AI) H5 gene from A/turkey/WI/68 (AdTW68.H5ck). Commercial, layer-type chicken groups were either singly vaccinated ocularly at 5 days of age, singly vaccinated via spray at 5 days of age, or ocularly primed at 5 days and ocularly boosted at 15 days of age. Only chickens primed and boosted via the ocular route developed AI systemic antibodies with maximum hemagglutination inhibition mean titers of 3.9 log2 at 32 days of age. In contrast, single vaccination via the ocular or spray routes maintained an antibody status similar to unvaccinated controls. All chickens (16/16) subjected to ocular priming and boosting with AdTW68.H5ck survived challenge with highly pathogenic AI virus A/chicken/Queretaro/14588-19/95 (H5N2). Single ocular vaccination resulted in 63% (10/16) of birds surviving the challenge followed by a 44% (7/16) survival of single-sprayed vaccinated birds. Birds vaccinated twice via the ocular route also showed significantly lower (P < 0.05) AI virus RNA concentrations in oropharyngeal swabs compared to unvaccinated-challenged controls.
authors.affiliation: Department of Pathobiology, Auburn University College of Veterinary Medicine, 264 Greene Hall, Auburn, AL 36830, USA. torohar@auburn.edu
authors.forename: Haroldo
authors.initials: H
authors.lastname: Toro
authors.forename: David L
authors.initials: DL
authors.lastname: Suarez
authors.forename: De-chu C
authors.initials: DC
authors.lastname: Tang
authors.forename: Frederik W
authors.initials: FW
authors.lastname: van Ginkel
authors.forename: Cassandra
authors.initials: C
authors.lastname: Breedlovea
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000375:Aging; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002645:Chickens; D004333:Drug Administration Routes; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology*; D007117:Immunization, Secondary; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D005585:Influenza in Birds / Q000517:prevention & control*; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*; D014779:Virus Replication / Q000235:genetics
chemical_list: D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D019444:Vaccines, DNA