title: Intraocular vaccination with an inactivated highly pathogenic avian influenza virus induces protective antibody responses in chickens.
abstract: Because it is expected to induce cross-reactive serum and mucosal antibody responses, mucosal vaccination against highly pathogenic avian influenza (HPAI) is potentially superior to conventional parenteral vaccination. Here, we tested whether intraocular vaccination with an inactivated AI virus induced protective antibody responses in chickens. Chickens were inoculated intraocularly twice with 10(4) hemagglutination units of an inactivated H5N1 HPAI virus. Four weeks after the second vaccination, the chickens were challenged with a lethal dose of the homologous H5N1 HPAI virus. Results showed that most of the vaccinated chickens mounted positive antibody responses. The median serum hemagglutination inhibition titer was 1:80. Addition of CpG oligodeoxynucleotide 2006 or cholera toxin to the vaccine did not enhance serum antibody titers. Cross-reactive anti-hemagglutinin IgG, but not IgA, was detected in oropharyngeal secretions. In accordance with these antibody results, most vaccinated chickens survived a lethal challenge with the H5N1 HPAI virus and did not shed the challenge virus in respiratory or digestive tract secretions. Our results show that intraocular vaccination with an inactivated AI virus induces not only systemic but also mucosal antibody responses and confers protection against HPAI in chickens.
authors.affiliation: National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0854, Japan. hhikono@affrc.go.jp
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hikono
authors.forename: Masaji
authors.initials: M
authors.lastname: Mase
authors.forename: Aya
authors.initials: A
authors.lastname: Matsuu
authors.forename: Megumi
authors.initials: M
authors.lastname: Nakayama
authors.forename: Takehiko
authors.initials: T
authors.lastname: Saito
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000097:blood; D000918:Antibody Specificity; D002645:Chickens / Q000276:immunology* / Q000821:virology*; D003429:Cross Reactions; D018928:Immunity, Mucosal; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology* / Q000472:pathogenicity; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology; D005585:Influenza in Birds / Q000276:immunology* / Q000517:prevention & control*; D007273:Injections, Intramuscular; D009883:Ophthalmic Solutions; D009960:Oropharynx / Q000276:immunology; D014611:Vaccination / Q000379:methods / Q000662:veterinary; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines; D009883:Ophthalmic Solutions; D015164:Vaccines, Inactivated