title: Priming with a DNA vaccine delivered by attenuated Salmonella typhimurium and boosting with a killed vaccine confers protection of chickens against infection with the H9 subtype of avian influenza virus.
abstract: Control of the circulation of H9 low-pathogenic avian influenza virus (LPAIV) is a major concern for both animal and public health. To improve vaccine efficacy against H9 LPAIV, we have utilized a novel prime-boost vaccination strategy. Specific-pathogen free (SPF) chickens were first orally immunized with a hemagglutinin (HA) DNA vaccine delivered by attenuated Salmonella typhimurium, followed by boosting with a killed avian influenza (AI) vaccine. Chickens in this combined vaccination group were completely protected against both oropharyngeal and cloacal virus shedding after intranasal challenge with H9N2 AIV, while viruses were detected from these sites in other vaccination groups. Prior to challenge, chickens in the prime-boost group also had higher (P<0.05) serum hemagglutination inhibition (HI) titers and intestinal mucosal IgA ELISA titers against AIV, and higher lymphoproliferation stimulation indices than those from other groups. Thus, we have demonstrated the efficacy of a novel prime-boost vaccination strategy against H9N2 avian influenza virus, which could be also applied for the development of vaccines against other mucosally infectious pathogens.
authors.affiliation: Jiangsu Key Laboratory of Zoonosis, Yangzhou University, 12 East Wenhui Road, Yangzhou, Jiangsu 225009, PR China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Pan
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.forename: Shizhong
authors.initials: S
authors.lastname: Geng
authors.forename: Ningning
authors.initials: N
authors.lastname: Cheng
authors.forename: Lin
authors.initials: L
authors.lastname: Sun
authors.forename: Beibei
authors.initials: B
authors.lastname: Liu
authors.forename: Jinlin
authors.initials: J
authors.lastname: Huang
authors.forename: Xinan
authors.initials: X
authors.lastname: Jiao
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002645:Chickens; D002988:Cloaca / Q000821:virology; D006385:Hemagglutination Inhibition Tests; D007117:Immunization, Secondary; D053127:Influenza A Virus, H9N2 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D005585:Influenza in Birds / Q000517:prevention & control* / Q000821:virology; D009960:Oropharynx / Q000821:virology; D012486:Salmonella typhimurium / Q000235:genetics; D013047:Specific Pathogen-Free Organisms; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*; D015164:Vaccines, Inactivated; D017201:Virus Shedding / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines; D019444:Vaccines, DNA; D015164:Vaccines, Inactivated