Preparation and immunogenicity of antigen-antibody complex of avian influenza virus.

Objective To prepare antigen-antibody complex of avian influenza virus and determine its immunogenicity.Methods Yolk antibody was prepared by immunizing hens with HA protein of avian influenza virus subtype H5, and mixed with HA protein at various ratios.SPF chickens at 1 d of age were immunized with the prepared antigen-antibody complex and challenged with avian influenza virus strain A / Environment / Qinghai / 1 / 2008(H5N1)to observe the protective effect.The HI antibody titers in sera of chickens were determined on various days after immunization and compared with those of chickens immunized with inactivated avian influenza H5 virus oil-emulsion vaccine.Results The mean antibody level of chickens 15 d after immunization with antigenantibody complex at a concentration ratio of 1 ∶ 0.6 reached 6.5 log2, which showed no significant difference with that of chickens immunized with inactivated avian influenza H5 virus oil-emulsion vaccine.Both the protective rates of the prepared antigen-antibody complex and inactivated avian influenza H5 virus oil-emulsion vaccine against the challenge with avian influenza virus at equal concentrations were 93.3%.Conclusion The prepared antigen-antibody complex of avian influenza virus showed good immunogenicity, which provided a basis for development of novel avian influenza virus complex vaccines.