Study on the bactericidal antibody against Neisseria meningitidis serogroup C strains after immunization with a divalent polysaccharide (A plus C) vaccine
10.3760/cma.j.issn.0254-6450.2009.06.020
- VernacularTitle:C群脑膜炎奈瑟菌血清杀菌力试验的优化及其应用
- Author:
Li XU
1
;
Long-Ze LUO
;
Bing-Qing ZHU
;
Li HE
;
Yuan GAO
;
Zhu-Jun SHAO
Author Information
1. 中国疾病预防控制中心传染病预防控制所
- Keywords:
Neisseria meningitidis;
Serum bacteriacidal assay;
Antibody
- From:
Chinese Journal of Epidemiology
2009;30(6):619-621
- CountryChina
- Language:Chinese
-
Abstract:
Objective To optimize the serum bactericidal assay (SBA) , detect and analyze the bactericidal antibody level against Neisseria meningitidis serogroup C strains after divalent polysaccharide (A plus C) vaccine immunization. Methods Two Neisseria meningitidis serogroup C strains, vaccine candidate strain (C11) and epidemic strain (053442), were selected as targets. The national Neisseria meningitidis standardized serum was used as reference serum. Pel-Freez infant rabbit complements was available. The optimized SBA method was used to detect bactericidal antibody against strain C11 and 053442 for 122 pairs of sera before and after immunization with a divalent polysaccharide (A and C) vaccine. Results The strain C11 and 053442 both could be used as targeted strain for SBA. The optimized concentration of targeted strain was achieved when a whole-cell suspension of 0.35 A at 600 nm was diluted 4×104 times. Before immunization, SBA geometric mean titers(GMT) of 122 sera against strain C11 and 053442 were 1: 1.75 and 1:2.63 respectively, and the protective rates were 9.8% and 17.2% respectively. After immunization, the GMTs and the protective rates of 122 sera both rose significantly (P<0.01), the GMTs against strain C11 and 053442 were 1:483.73 and 1:412.57 respectively. The protective rates against strain C11 and 053442 were 100% and 95.9% respectively. Conclusion Immunization with a divalent polysaccharide (A and C) vaccine could elevate remarkably the population SBA titer against Neisseria meningitidis serogroup C strains of different subtypes, but the surveillance of vaccine effect against different targeted strains remains necessary.
