Quality control of pneumococcal Polysaccharide-protein c

摘要：用散射比浊法测定多价结合疫苗中PS的含量，确定了PSS和抗体的最佳浓度条件。高碘酸氧化是共轭过程中重要的第一步。因此，高碘酸盐活化的PSS的免疫化学特征可以提供整个结合过程中稳定性的早期指示。 对于多价PS和PS-蛋白结合疫苗中PS含量的控制测试，重要的是要有(I)每种PS和单价结合物的参考标准，(Ii)每种PS的特异性抗血清。用灭活全肺炎球菌制备的兔抗血清对多种类型肺炎链球菌PSS的分散率具有很高的敏感性。光散射比浊法为单价和多价肺炎球菌结合疫苗中PS含量的定量分析提供了一种准确、重现性好的方法。该方法适用于用苯基-琼脂糖层析法或其他合适的方法从PS蛋白结合物中分离出游离糖后，测定结合疫苗中的游离糖含量。 在一些获得许可的生物制品中，疫苗的容器和稀释剂已通过伽马辐照进行灭菌。它已被用于血液制品的灭菌和病毒灭活，以及清除细胞系中的外源物质。本研究的目的是通过分子大小和小鼠免疫原性来检测辐射灭菌对细菌PS和PS蛋白结合疫苗效力的影响。 用伽马、电子束和X射线照射三种不同的疫苗，即嗜血杆菌b结合物疫苗、6B型肺炎链球菌PS疫苗和伤寒Vi PS疫苗(25kGy3种)。一般来说，辐射增加了Kd值，表明Hib结合物、6B型肺炎球菌PS和伤寒Vi PS疫苗的分子尺寸减小。尽管在24kGy伽马照射下分子尺寸减小，但小鼠对Hib结合疫苗的抗体应答没有明显变化。电子束辐照样品的KD仍符合肺炎球菌6B型PS和伤寒Vi PS疫苗的产品规格。

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.