Sabin株脊髓灰质炎病毒灭活疫苗的制备及免疫原性评价

目的  建立Sabin株毒种制备脊髓灰质炎灭活疫苗（inactivated poliovirus vaccine, IPV）生产工艺并评价其免疫原性。方法  采用Vero细胞培养Sabin株脊髓灰质炎Ⅰ、Ⅱ、Ⅲ型病毒，制备3价Sabin株IPV（Sabin strain IPV, sIPV）。通过ELISA检测D抗原含量。检测病毒滴度，电子显微镜下观察纯化病毒形态并电泳鉴定，分析抗原纯度，同时检测纯化原液宿主细胞残余DNA和蛋白含量。通过大鼠体内接种法比较sIPV和野生株IPV免疫原性，并观察中和抗体滴度变化。结果 Ⅰ、Ⅱ、Ⅲ型收获液D抗原含量分别为2 437、365、1 253 DU/ml，病毒滴度分别为每毫升8.4 、7.8和7.9 lg半数细胞培养物感染量。纯化病毒抗原纯度均﹥99%。电子显微镜下观察可见直径20~30 nm病毒颗粒，电泳鉴定正确。纯化原液的残余宿主细胞DNA和蛋白含量分别12.3 pg/500 μl和9.8 ng/ml。sIPV 3针免疫后在大鼠体内诱导产生抗Ⅰ、Ⅱ、Ⅲ型中和抗体的几何平均滴度分别为9 397.8、554.7和4 668.4，与野生株IPV相比Ⅰ型明显增高（t=-3.429,P=0.004），Ⅱ、Ⅲ型无明显差别，初免后19周内均维持在较高水平。结论 建立了稳定的sIPV生产工艺，制备的sIPV免疫原性较好。

Preparation and immunogenicity evaluation of Sabin strain inactivated polio virus vaccine#br#

 To establish the production process of inactivated poliovirus vaccine derived from Sabin strain and evaluate the immunogenicity of Sabin strain IPV (sIPV). Methods  Types Ⅰ, Ⅱ, and Ⅲ Sabin strain polioviruses were cultured in Vero cells to prepare trivalent sIPV. D antigen contents of sIPV were quantified by ELISA. Virus titers were tested. Virus was identified by electron microscope and electrophoresis. Antigen purity was tested. Host cell DNA and protein contents were determined. Immunogenicity of sIPV was compared with wildtype IPV by potency test in rats. Dynamic changes of neutralizing antibody titer were observed. Results  D antigen contents of types Ⅰ, Ⅱ, and Ⅲ polioviruses were 2 437, 365, and 1 253 DU/ml, and average virus titers were 8.4 , 7.8, and 7.9 lg 50% cell culture infectious dose per ml, respectively. The purity of purified virus fluid was ﹥99%. By electron microscopy, 20-30 nm diameter virus particles were observed and confirmed by electrophoresis. Residual DNA content and host cell protein content of purified virus fluid were 12.3 pg/500 μl and 9.8 ng/ml,respectively. The geometric mean titers (GMTs) of neutralizing antibodies against typeⅠ, Ⅱ, and Ⅲ induced by 3 injections of sIPV were 9 397.8, 554.7, and 4 668.4, respectively, significantly higher than that of wildtype IPV for type I (t=-3.429,P=0.004), and no significant difference for type Ⅱand type Ⅲ. The neutralizing antibody GMTs kept at a higher level within 19 weeks after primary immunization. Conclusion  A stable production process of sIPV is developed and the vaccine products have good immunogenicity.