Quality control of pneumococcal Polysaccharide-protein c

总结： 为了用比浊法定量测定多价结合疫苗中的PS含量，确定了PS和抗体的最佳浓缩条件。 高碘酸盐氧化是缀合过程中重要的第一步。 因此，高碘酸盐活化PS的免疫化学表征可以提供总缀合过程中稳定性的早期指示。 对于多价PS和PS-蛋白结合物疫苗中PS含量的控制检测，重要的是具有（i）每种类型PS和单价结合物的参考标准品，（ii）每种类型PS的参考特异性抗血清。 在用灭活的完整肺炎球菌超免疫家兔制备的抗血清中，在许多类型的肺炎球菌PS中观察到散射率的高灵敏度。 光散射比浊法是一种准确、重复性好的定量分析单价和多价肺炎球菌结合疫苗中PS含量的方法。 通过苯基琼脂糖色谱法或其他合适的方法从PS-蛋白结合物中分离游离糖后，该方法可适用于测定结合物疫苗中的游离糖含量。 在一些许可的生物制品中，疫苗的容器和稀释剂已通过伽马辐照灭菌。 它已被用于血液制品的灭菌和病毒灭活以及细胞系中外源因子的消除。 本研究的目的是检查辐射灭菌对细菌PS和PS-蛋白结合物疫苗效价的影响，通过分子大小和小鼠免疫原性进行测量。 三种不同的疫苗，嗜血杆菌B结合物、肺炎球菌6型B PS和伤寒Vi PS疫苗使用γ、电子束和X射线源进行辐照（25 kGy）。 一般而言，照射增加了Kd值，表明Hib结合物、6 B型肺炎球菌PS和伤寒Vi PS疫苗的分子大小减小。 虽然分子大小在24 kGy的γ辐照下减小，但Hib缀合物疫苗的小鼠IgG和IgM抗体应答没有显著变化。 电子束辐照样品的Kd仍符合6 B型肺炎球菌PS和伤寒Vi PS疫苗的产品质量标准。

Summary: For quantitation of PS content in polyvalent conjugate vaccines by nephelometry, the optimum conditions of concentration for PSs and antibodies were determined. Periodate oxidation is an important first step in the conjugation process. Thus, immunochemical characterization of periodate activated PSs can provide an early indication of stability in total conjugation process. For control testing of PS content in polyvalent PS and PS-protein conjugate vaccines, it is important to have (i) reference standard for each type of PS and monovalent conjugate, (ii) reference specific antiserum to each type of PS. High sensitivity of the scattering rate was observed in many types of pneumococcal PSs using antisera, which were prepared in rabbits hyperimmunized with inactivated whole pneumococci. Light scattering rate nephelometry provides an accuarate and reproducible method for quantitative analysis of PS content in monovalent and polyvalent pneumococcal conjugte vaccines. This method can be adapted to measure the free saccharide content in conjugate vaccine after the free saccharide is separated from the PS-protein conjugate by phenyl-sepharose chromatography or another suitable method. In some licensed biologics, containers and diluent for vaccines have been sterilized by gamma irradiation. It has been used for the sterilization and viral inactivation of blood products and elimination of adventitious agents in cell lines. The objective of the present study was to examine the effect of radiation sterilization on the potency of bacterial PS and PS-protein conjugate vaccines as measured by molecular size and mouse immunogenicity. Three different vaccines, Haemophilus b conjugate, pneumococcal type 6B PS, and typhoid Vi PS vaccines were irradiated (25 kGy) using gamma, electron beam and X-ray sources. In general, irradiation increased the value of the Kd, indicating a decrease in the molecular size of the Hib conjugate, pneumococcal type 6B PS and the typhoid Vi PS vaccines. Although the molecular size decreased under gamma irradiation at 24 kGy, the mouse IgG and IgM antibody responses for the Hib conjugate vaccine did not significantly change. The Kd's for the electron beam irradiated samples still met the product specifications for pneumococcal type 6B PS and typhoid Vi PS vaccine.