建立膜抗原荧光抗体试验评价北京株冻干水痘疫苗免疫效果

为了建立用于水痘疫苗接种后血清中特异性抗体检测的膜抗原荧光抗体(FAMA)法,并对接种水痘疫苗后儿童血清中水痘特异性抗体进行检测,评价北京株水痘疫苗的免疫效果。以水痘带状疱疹病毒(VZV)感染细胞作为抗原制备成固定抗原玻片,以异硫氰酸荧光素(FITC)标记的羊抗人IgG作为二抗建立FAMA法,并对该法的敏感性、特异性进行验证。运用此法对不同剂量北京株水痘疫苗接种后儿童血清中特异性抗体进行检测,分析儿童血清中水痘特异性抗体水平以及免后抗体阳转率,并与Oka株水痘疫苗进行比较。结果显示,FAMA法敏感性可达0.0196IU/ml,特异性好。应用此法检测300名观察者免前免后双份血清样本中抗VZVIgG,易感者中北京株水痘疫苗原苗(39810PFU/0.5ml)、2000PFU/0.5ml、500PFU/0.5ml接种组儿童血清免后抗体阳转率分别为100%、98.77%、85.42%,抗体几何平均滴度(GMT)分别为36.4、34.3、18.6,原苗与2000PFU间的抗体阳转率和GMT均无显著性差异(P>0.05),但原苗与500PFU、2000PFU与500PFU间的抗体阳转率和GMT均有显著性差异(P<0.05)。对照国产、进口Oka株水痘疫苗接种后抗体阳转率分别为95.35%、96.97%,抗体GMT分别为13.3、16.0,不同剂量北京株疫苗抗体阳转率与国产、进口Oka株疫苗相比,差别无显著性(P>0.05),但北京株疫苗原?

The immune efficacy of Beijing strain varicella vaccine evaluated by FAMA test

To develop a technique of fluorescent antibody to membrane antigen(FAMA) for the detection of varicella-zoster virus(VZV) antibody in the sera of children inoculated by varicella vaccine, and evaluate the immune efficacy of Beijing strain varicella vaccine. The FAMA test was established with VZV infected cells as fixed antigen and FITC labeled goat anti-human IgG as the second antibody. The sensitivity and specificity were validated. The level and positive seroconverted rate of anti-VZV IgG in sera of children immunized with Beijing strain were analyzed, and compared with those for Oka strain vaccine. FAMA test has a high sensitivity for which the lowest detecting limit is 0.0196 IU/ml, and is more specific in that no cross reaction with other herpsviruses were detected. Anti-VZV IgG in the sera of 300 vaccinees were detected by FAMA. The positive seroconverted rates in susceptible groups immuinized with Beijing strain with 39810PFU、2000PFU and 500PFU are 100%, 98.77%, 85.42% respectively, and the genometric mean titer (GMT) of them are 36.4, 34.3,(18.6) respectively.The difference of positive seroconverted rates and GMT has no significance (P>0.05) , but is significant between 39810PFU and 2000PFU, 2000PFU and 500PFU respectively (P<0.05). Comparatively, the positive seroconverted rate of the control for domestic and imported Oka strain vaccines were 95.35% and 96.97% respectively, which has no significant difference between them (P>0.05), and has no significant difference between each control and each dose group of Beijing strain. The antibody GMT of domestic and imported Oka strain are 13.3 and 16.0 respectively, which are significantly lower than that of 39810PFU and 2000PFU (P<0.05), and has no significant difference between each control group and 500PFU (P>0.05) as well as between both of the control group. The fourfold increasing rates of antibody in non-susceptible groups of 39810PFU、2000PFU and 500PFU are 100%, 92.90%, 75.0% respectively,and for the control domestic and imported Oka strain vaccines were 100%and 83.8% respectively. The developed FAMA test is both sensitive and specific. Beijing strain varicella vaccine has a good immune efficacy and can be used for susceptible people.