目的  比较以1-氰基-4-二甲氨基吡啶四氟硼酸盐（1-cyano-4-dimethylamino pyridine tetrafluoroborate，CDAP）和溴化氰（cyanogen bromide，CNBr）为活化剂制备的4型肺炎球菌多糖（type 4 pneumococcal polysaccharide，PS4）-白喉类毒素（diphtheria toxoid，DT）结合物（PS4-DT）原液的免疫原性。方法  分别以CDAP或CNBr为活化剂，各制备1批PS4-DT原液，并对原液的相关质量指标进行检测。分别用2种PS4-DT原液，间隔2周皮下注射NIH小鼠3次，末次免疫1周后采集血清，用ELISA检测血清抗体水平，比较不同方法制备的2种PS4-DT原液的免疫原性。结果  2种PS4-DT原液的主要质量指标均符合相关规定的要求，结合PS4的含量分别为257.1和203.1 μg/ml。2种PS4-DT原液均可与PS4抗血清发生特异性反应。抑制ELISA检测显示，2种PS4-DT原液对PS4抗血清的抑制率均达到100%。2种PS4-DT原液免疫小鼠产生的抗PS4抗体水平相近，抗体几何平均滴度分别为970.06和844.49。 结论  不同种方法制备的2种PS4-DT原液在小鼠中的免疫原性相似，且均可诱导小鼠产生较高水平的抗体。

Objective  To compare the immunogenicity of type 4 pneumococcal polysaccharide (PS4) - diphtheria toxoid (DT) conjugates (PS4-DT) prepared with 1-cyano-4-dimethylamino pyridine tetrafluoroborate (CDAP) and cyanogen bromide (CNBr) as activators. Methods  One batch each of PS4-DT bulk was prepared with CDAP or CNBr as activator, and the relevant quality indexes of 2 PS4-DT bulks were detected. NIH mice were given 3 subcutaneous injections with either of PS4-DT bulks every 2 weeks. The mice sera were collected 1 week after the last immunization. The serum antibody titers were detected by inhibition ELISA, and the immunogenicities of PS4-DT bulks prepared by different methods were compared. Results  The main quality indexes of both PS4-DT bulks met relevant requirement standards, and the conjugated PS4 contents in PS4-DT bulks were 257.1 and 203.0 μg/ml, respectively. Both PS4-DT bulks  specifically reacted with PS4 anti-sera. The inhibition ELISA showed that the inhibition rates of both PS4-DT bulks for PS4 anti-sera reached 100%. The anti-PS4 levels induced by mice immunized with 2 PS4-DT bulks were similar, and antibody geometric mean titers were 970.06 and 844.49, respectively. Conclusion  The immunogenicities of PS4-DT bulks prepared by the different methods are similar in mice, and both can induce high antibody levels in immunized mice.