A new 15-valent pneumococcal conjugate vaccine (PCV15) against serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 11A, 14, 18C, 19A, 19F, 22F, and 23F has been developed using aluminum phosphate as an adjuvant. Using the rabbit model, immunogenicity of each serotype was evaluated by measuring antigen specific antibodies and functional antibody titers and comparing them to a control vaccine, Prevnar13®. Among the shared serotypes in both PCV15 and Prevnar13®, Type 3 and 23F in PCV15 exhibited a lower opsonic index than Prevnar13®. Conversely, the other types showed greater or nearly the same immunogenic effects. Type 11A and 22F are two additional serotypes included in PCV15, and only 22F showed a reasonable opsonic index compared with other types. Type 11A exhibited a basal level fold-increase in OPA; thus, we further optimized 11A as well as 3 and 23F by controlling the polysaccharide-to-protein conjugation ratio as a variable. Antibody levels and functional antibody activities were evaluated by ELISA and OPA, and improved levels of immunogenic activities were observed for all three serotypes. In this study, we propose a new PCV15 candidate, in which the common 13 serotypes and a licensed control vaccine have equivalent efficacy while two additional serotypes showed adequate immunogenicity in the rabbit model.

已经使用磷酸铝开发了针对血清型1、3、4、5、6A，6B，7F，9V，11A，14、18C，19A，19F，22F和23F的新型15价肺炎球菌结合疫苗（PCV15）。佐剂。使用兔模型，通过测量抗原特异性抗体和功能抗体滴度并将其与对照疫苗Prevnar13®进行比较，评估每种血清型的免疫原性。在PCV15和Prevnar13®共有的血清型中，PCV15的3型和23F表现出比Prevnar13®更低的调渗指数。相反，其他类型显示出更大或几乎相同的免疫原性作用。11A和22F型是PCV15中包括的另外两种血清型，与其他类型相比，只有22F表现出合理的声波指数。11A型在OPA中表现出基础水平的倍增；从而，我们通过控制多糖与蛋白质的结合率作为变量来进一步优化11A以及3和23F。通过ELISA和OPA评估了抗体水平和功能性抗体活性，并观察到所有三种血清型的免疫原性水平均得到改善。在这项研究中，我们提出了一种新的PCV15候选物，其中常见的13种血清型和许可的对照疫苗具有相同的功效，而另外两种血清型在兔模型中显示出足够的免疫原性。