PNEUMOCOCCAL POLYSACCHARIDE PROTEIN CONJUGATE VACCINES

最近获得许可的肺炎球菌结合疫苗含有7种不同类型（4，6 B，9V，14，18 C，19 F和23 F）与CRM 197蛋白结合。 通过速率散射比浊法的免疫化学测定用于评价多价肺炎球菌疫苗中的单个PS含量。 散射光度法测量散射光穿过沉淀素反应形成的抗原-抗体复合物时的强度。 为了通过比浊法定量PS含量，需要确定PS和抗体的最佳浓度。 因此，本研究的目的是确定定量测定多价PS-蛋白结合物疫苗中单个PS的最佳条件。 用胰蛋白酶处理多价缀合物疫苗以消化载体蛋白，从而将PS释放到溶液中。作为参考，用胰蛋白酶处理10 μ g/ml单价缀合物疫苗，并将释放的PS稀释至不同浓度。(0.5至10 μ g/ml）使用的抗血清是针对每种肺炎球菌类型的类型特异性超免疫兔血清。 4、6 B、9V、14、18 C、19 F和23 F型PS的标准曲线在0.5至10 μ g/ml范围内与PS浓度的增加成比例。 过量或高PS浓度导致沉淀素反应的抑制和Ag-Ab复合物的减少，从而降低散射率。 发现这7种PS类型的最佳浓度为1-5 μ g/ml，当与它们各自的抗血清一起使用时显示线性。 速率散射比浊法操作简单，使用少量的抗原和抗体，并产生可重复的和准确的数据，用于多价疫苗中单个PS的定量分析。 然而，它需要PS抗原的参考标准和特异性高滴度抗血清。 正在检查可能干扰浊度免疫测定系统的物质和条件。

The recently licensed pneumococcal conjugate vaccine contains 7 different types (4, 6B, 9V, 14, 18C, 19F, and 23F) conjugated to CRM197 protein. The immunochemical assay by rate nephelometry is being used for evaluation of individual PS content in polyvalent pneumococcal vaccines. Nephelometry measures the intensity of scattered light as it is passed through the antigen-antibody complex formed by the precipitin reaction. For quantitation of PS content by nephelometry, the optimum concentrations for PSs and antibodies need to be determined. The objective of the present study was therefore to determine the optimum conditions for quantitative determination of individual PS in a polyvalent PS-protein conjugate vaccine. A multivalent conjugate vaccine was treated with trypsin to digest the carrier protein, thus releasing PSs into solution. For reference, monovalent conjugate vaccines, 10 ug/ml, were treated with trypsin and the released PSs diluted to different concentrations.(0.5 to 10 ug/ml) The antisera used were type specific hyperimmune rabbit sera against each pneumococcal type. Standard curves for types 4, 6B, 9V, 14, 18C, 19F, and 23F PSs were proportional to the increase of PS concentration in the range of 0.5 to 10 ug/ml. An excess or high PS concentration resulted in inhibition of the precipitin reaction and a reduction in the Ag-Ab complexes and thereby a decreased scattering rate. The optimum concentration for these 7 PS types, displaying linearity when used with their respective antisera, was found to be 1-5 ug/ml. Rate nephelometry is simple in operation, utilizes small quantities of antigen and antibody, and yields reproducible and accurate data for the quantitative analyses of individual PSs in polyvalent vaccines. However, it requires the reference standards for PS antigens and specific high titered antisera. Substances and conditions that may interfere with the nephelometric immunoassay system are being examined.