Simell Birgit, Nurkka Anu, Ekström Nina, Givon-Lavi Noga, Käyhty Helena, Dagan Ron
Department of Vaccination and Immune Protection, National Institute for Health and Welfare, Helsinki, Finland.
Clin Vaccine Immunol. 2012 Oct;19(10):1618-23. doi: 10.1128/CVI.00248-12. Epub 2012 Aug 8.
In immunogenicity trials of pneumococcal conjugate vaccines (PCVs), only IgG antibody concentrations to pneumococcal capsular polysaccharides (PPSs) are usually determined, along with the opsonophagocytic activity (OPA) of antipneumococcal antibodies. We aimed to determine the role of both IgG and IgM in OPA in toddlers receiving one dose of 9-valent PCV (PCV9). The IgG and IgM antibody concentrations to PPSs of serotypes 6A, 9V, 14, 19F, and 23F were measured by enzyme immunoassay in sera from toddlers (ages 18 to 35 months) 1 month after a single PCV9 dose. The OPA for the same serotypes was measured by multiplexed opsonophagocytosis assay (MOPA). Further, IgG and IgM concentrations and MOPA were measured to PPS of serotypes 6A, 14, and 19F in sera collected 12 months after vaccination. The detected MOPA titers were high in comparison to the IgG concentrations 1 month after immunization. The IgM concentrations were higher than IgG concentrations for serotypes 6A and 14 (P < 0.001) and as high as IgG for serotypes 9V, 19F, and 23F. Correlation of the IgM antibody concentrations with MOPA (r = 0.35 to 0.65) was stronger compared to that of the IgG antibodies (r = 0.07 to 0.41). The depletion of IgG antibodies in three sets of pooled sera only slightly decreased the OPA activity against serotype 14. At 12 months after immunization, 50 to 100% of serum samples still showed detectable MOPA activity against serotypes 6A, 14, and 19F. Our results suggest that IgM contributes to OPA 1 month after a single PCV9 vaccination in toddlers and that functionally active IgM and IgG antibodies persist for at least a year.
在肺炎球菌结合疫苗（PCV）的免疫原性试验中，通常只测定针对肺炎球菌荚膜多糖（PPS）的IgG抗体浓度以及抗肺炎球菌抗体的调理吞噬活性（OPA）。我们旨在确定IgG和IgM在接受一剂9价PCV（PCV9）的幼儿OPA中的作用。通过酶免疫测定法测量了18至35个月大幼儿在单剂PCV9接种1个月后血清中针对6A、9V、14、19F和23F血清型PPS的IgG和IgM抗体浓度。通过多重调理吞噬试验（MOPA）测量了相同血清型的OPA。此外，在接种疫苗12个月后收集的血清中测量了针对6A、14和19F血清型PPS的IgG和IgM浓度以及MOPA。免疫后1个月检测到的MOPA滴度与IgG浓度相比很高。6A和14血清型的IgM浓度高于IgG浓度（P < 0.001），9V、19F和23F血清型的IgM浓度与IgG浓度一样高。与IgG抗体（r = 0.07至0.41）相比，IgM抗体浓度与MOPA的相关性更强（r = 0.35至0.65）。三组混合血清中IgG抗体的消耗仅略微降低了针对14血清型的OPA活性。免疫后12个月，50%至100%的血清样本仍显示出针对6A、14和19F血清型的可检测MOPA活性。我们的结果表明，IgM在幼儿单次接种PCV9疫苗1个月后对OPA有贡献，并且功能活跃的IgM和IgG抗体至少持续存在一年。
