title: Evaluation of avian paramyxovirus serotypes 2 to 10 as vaccine vectors in chickens previously immunized against Newcastle disease virus.
abstract: Newcastle disease virus (NDV), also known as avian paramyxovirus (APMV) serotype 1, is used as a vaccine vector to express the hemagglutinin protein of avian influenza (AI) virus. However, use of live NDV recombinant vaccines expressing AI virus hemagglutinin is not desirable in emergency vaccination programs to control severe AI outbreaks in chickens, because commercial chickens often possess pre-existing NDV immunity induced by routine vaccination. Therefore, a novel vaccine vector is required for emergency vaccination of chickens to control AI during outbreaks. We investigated whether candidate APMV strains could be used as vaccine vectors that could evade the pre-existing immunity acquired by chickens through NDV vaccination and that would replicate in the mucosal tissues where AI virus primarily replicates. To this end, we examined strains of APMV serotypes 2 to 10 for their immunogenicity and replication in chickens with pre-existing immunity to NDV. APMV serotypes 2, 6, and 10 were the least cross-reactive to antibodies to NDV in hemagglutination inhibition and/or virus neutralization tests. Virus replication in mucosal tissues, as well as antibody response after oculonasal inoculation, was observed when 7-week-old chickens were challenged with APMV of serotype 2, 6, or 10. The APMV also replicated in mucosal tissues and induced antibody responses in chickens that had been vaccinated twice with NDV before challenge. These results warrant further study to develop vaccine vectors based on APMV serotype 2, 6, or 10 for emergency vaccination of chickens against AI.
authors.affiliation: Influenza and Prion Disease Research Center, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0854, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Tsunekuni
authors.affiliation: Influenza and Prion Disease Research Center, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0854, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hikono
authors.affiliation: Influenza and Prion Disease Research Center, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0854, Japan. Electronic address: taksaito@affrc.go.jp.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Saito
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D000918:Antibody Specificity; D018109:Avulavirus / Q000145:classification / Q000235:genetics* / Q000276:immunology*; D002645:Chickens / Q000276:immunology / Q000821:virology; D003429:Cross Reactions; D005822:Genetic Vectors; D006385:Hemagglutination Inhibition Tests; D005585:Influenza in Birds / Q000276:immunology / Q000517:prevention & control; D009500:Neutralization Tests; D009522:Newcastle disease virus / Q000276:immunology*; D012703:Serotyping; D014614:Vaccines, Synthetic / Q000235:genetics; D014765:Viral Vaccines / Q000235:genetics*; D014779:Virus Replication; D017201:Virus Shedding
chemical_list: D000914:Antibodies, Viral; D014614:Vaccines, Synthetic; D014765:Viral Vaccines
keywords: APMV; Antibody response; Avian paramyxovirus; NDV; Newcastle disease virus; Vaccine vector