title: Neutralizing antibody but not hemagglutination antibody provides accurate evaluation for protective immune response to H5N1 avian influenza virus in vaccinated rabbits.
abstract: In order to develop an animal model and an assay method to evaluate protective immune response to H5N1 avian influenza vaccination, H5N1 avian influenza vaccine was prepared. New Zealand rabbits were assigned to receive two doses of vaccine with different hemagglutinin (HA) dosage. The sera from vaccinated rabbits was evaluated to determine antibody titer and specificity using different tested methods including hemagglutination inhibition assay (HI), neutralizing assay (NT), cross-HI assay, cross-single immunodiffusion assay and cross-neutralization assay. The titer of HI antibody from rabbits immunized with different doses of HA were no less than 1:40 among groups 14 days after the first immunization. Whereas the NT antibody titer was less than 1:10 among groups 14 days after the first immunization. NT antibodies can be detected 14 days after the second immunization in rabbits immunized at HA doses higher than 6 μg, and the NT antibody titers were equal to or higher than 1:40. A good concentration-dependent NT antibody response can be detected in the vaccinated rabbits 14 days after the second immunization, and in contrast, no concentration-dependent relationship can be seen for HA antibody. The cross-HI test showed sera from vaccinated rabbits could cross react with influenza A H5N1 virus with the titers higher than 1:40. No cross reaction among different types (influenza A/H1N1 virus, influenza A/H3N2 virus, influenza B virus and influenza A/H5N1 virus) can be detected in the sera using the single immunodiffusion assay and using NT antibody test. This showed NT antibody test was demonstrated as a more accurate assay method for evaluating vaccination and quality of the vaccine than HI antibody test.
authors.affiliation: Key Lab of Vaccine Against Hemorrhagic Fever with Renal Syndrome, Zhejiang Province Center for Disease Prevention and Control, Hangzhou 310009, China.
authors.forename: Hanping
authors.initials: H
authors.lastname: Zhu
authors.forename: Xiaohang
authors.initials: X
authors.lastname: Ding
authors.forename: Xuekui
authors.initials: X
authors.lastname: Chen
authors.forename: Pingping
authors.initials: P
authors.lastname: Yao
authors.forename: Fang
authors.initials: F
authors.lastname: Xu
authors.forename: Ronghui
authors.initials: R
authors.lastname: Xie
authors.forename: Zhanynv
authors.initials: Z
authors.lastname: Yang
authors.forename: Weifeng
authors.initials: W
authors.lastname: Liang
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yanjin
authors.initials: Y
authors.lastname: Li
authors.forename: Jiyou
authors.initials: J
authors.lastname: Shen
authors.forename: Peijiang
authors.initials: P
authors.lastname: He
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Guo
authors.forename: Bo
authors.initials: B
authors.lastname: Su
authors.forename: Shubin
authors.initials: S
authors.lastname: Sun
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood*; D000914:Antibodies, Viral / Q000097:blood*; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003429:Cross Reactions; D006385:Hemagglutination Inhibition Tests; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000008:administration & dosage / Q000276:immunology*; D005779:Immunodiffusion; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D009981:Influenza B virus / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D009500:Neutralization Tests; D011817:Rabbits; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000276:immunology
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D022223:Vaccines, Subunit