明胶微球乙肝疫苗动物免疫效果研究

Immunogenicity of gelatin microspheres encapsulated hepatitis B vaccine in animal trial

目的 研究并优化微球乙型肝炎疫苗的配方 ,观察微球乙肝疫苗对温度的稳定性。方法 用明胶包裹HBs制备微球 ,设计不同配方及不同粒径微球乙肝疫苗、冻干微球乙肝疫苗于不同温度放置一定时间 ,免疫动物观察免疫效果。结果 微球疫苗HBs包裹率 >90 % ,微球疫苗的免疫效果受佐剂配方及制备程序等因素影响 ,<10 μm的微球 (5 6 μm)免疫效果明显优于 >10 μm的微球(2 5 4μm) (P <0 0 2 )及铝佐剂组 (P <0 0 1)。接种动物后可维持高水平抗 HBsIgG抗体 (2 2 0～ 2 80mIU ml) 12个月以上 ;含铝佐剂的微球疫苗免疫效果优于不含铝的微球疫苗 (P <0 0 5 ) ;单纯明胶微球与HBs混合后免疫可增强抗 HBs反应 ,稍低于包裹HBs的微球组。冻干HBs微球对温度稳定性优于铝佐剂吸附HBs。结论 <10 μm的微球疫苗和含铝佐剂的微球疫苗可产生最佳的免疫效果 ;冻干微球疫苗可望解决铝佐剂吸附乙肝疫苗需要冷链的问题。

Objective To research and optimize the formulations of the microspheres encapsulated hepatitis B vaccine, and its stability to temperature. Methods Hepatitis B vaccine (HBs) was encapsulated in microspheres prepared from gelatin. The test animal were grouped and injected respectively with different sized microspheres blended HBs in various formulations and lyophilized. The lyophilized microspheres encapsulated HBs were kept under different temperatures for six months for observation of their stability. Results The encapsulation efficiency of the antigen was over 90%. The immunogenicity of the microspheres encapsulated HBs could be influenced by both the adjuvant formulations and the procedures of microspheres preparation. The small microspheres (<10μm) were significantly more immunogenic than the large microspheres(>10μm) (P<0.02) and Al(OH) 3 adsorbed HBs (Al HBs) (P<0.01), and the high titers of anti HBs were kept for over 12 months after injection. Microspheres encapsulated Al(OH) 3 and HBs could more effectively enhance anti HBs response than microspheres encapsulated HBs(P<0.05), and the mixture of microspheres encapsulated HBs and Al HBs(P<0.05). The formulation of plain microspheres plus HBs could more effectively enhance anti HBs response than Al HBs. Probably there was a positive correlation between the number of microspheres and anti HBs level. The lyophilized gelatin microspheres encapsulated HBs was more stable to temperature than Al HBs. Conclusions The small microspheres(<10μm) encapsulated HBs and microspheresencapsulated HBs and Al(OH) 3 can induce the strongest immune response. The formulation of the plain microsphere plus HBs had some advantages and deserved further research. The lyophilized microsphere encapsulated HBs is more stable to temperature compared to Al HBs, and it is presumed that the microspheres encapsulated HB vaccine can be transported without cold chain.