成人免疫ACYW135群脑膜炎球菌多糖疫苗后血清中抗体水平的动态分析

Dynamic evaluation of antibodies against serogroup A, C, Y and W135 strains in healthy adults im-munized with one dose of quadrivalent meningococcal polysaccharide vaccine

目的：从血清抗体体外杀菌功能和IgG含量角度观察健康成人接种一剂ACYW135群脑膜炎球菌多糖疫苗后不同时间体内抗体的动态水平，探讨抗体功能和含量的相关性和疫苗的保护期限。方法对20名健康成人接种一剂四价脑膜炎多糖疫苗，分别采集免疫前和免疫后不同时期的血清。采用血清杀菌试验（SBA）和标准定量酶联免疫吸附试验（ELISA）检测血清中杀菌抗体滴度和抗荚膜多糖IgG抗体含量。结果成人免疫前血清中存在一定水平的抗A、C、Y和W135群荚膜多糖抗体，并且除C群外，血清中针对A、Y和W135群球菌的杀菌抗体滴度都较高。免疫15d后，各群荚膜多糖抗体的含量和血清杀菌抗体滴度都较免疫前有了明显的升高（P＜0．05），并且在30～160d维持在较高的水平；免疫后近3年时杀菌抗体滴度和IgG抗体浓度降至免疫前水平。血清杀菌抗体滴度和IgG抗体浓度之间相关关系较弱（r＜0．3，P＞0．05），但免疫前后不同时间的受试者的血清杀菌抗体几何均数滴度（GMTs）和IgG抗体几何均数浓度（GMCs）之间具有良好的相关关系（r＞0．7，P＜0．05）。结论受试者免疫前后不同时间血清杀菌抗体GMTs和IgG抗体GMCs，在评价疫苗效果时具有一致性。接种ACYW135群脑膜炎球菌多糖疫苗有效期大约3年。

Objective To dynamically analyze the antibodies with regard to in vitro serum bacteri-cidal activity and the quantity of IgG in healthy adults received one dose of immunization with ACYW 135 me-ningococcal polysaccharide vaccine .To investigate the term of protection with polysaccharide vaccine and the correlation between bactericidal titer and IgG concentration .Methods Twenty healthy adults were given one dose of immunization with quadrivalent meningococcal polysaccharide vaccine .Serum samples were col-lected before and after vaccination at specific time points .Test for serum bactericidal activity （ SBA ） and quantitative ELISA were performed to detect bactericidal titers and IgG concentrations in serum samples .Re-sults Certain levels of antibodies against capsular polysaccharides of serogroup A , C, Y and W135 strains had already existed prior to immunization .Moreover, bactericidal titers against serogroup A , Y and W135 strains except serogroup C strain were relatively high .Specific IgG concentrations and bactericidal titers for all serogroup stains were significantly increased on day 15 after vaccination （P〈0.05）, and then sustained at a high level during a time period from day 30 to day 160.Both IgG concentrations and bactericidal titers dropped to the levels similar to that before preimmunization in about 3 years.No significant correlation was observed between bactericidal titers and IgG concentrations （r〈0.3, P〉0.05）.However, a close correla-tion was demonstrated between GMTs and GMCs of serum samples （r〉0.7, P〈0.05）.Conclusion The geometric mean titers （ GMTs） and geometric mean concentrations （ GMCs） of serum samples collected be-fore and after vaccination at different time points were reliable and consistent parameters for the evaluation of vaccine .The term of protection of quadivalent meningococcal polysaccharide vaccine was about 3 years upon a single dose of immunization .