论文部分内容阅读
目的:观察肠道病毒71型(enterovirus 71，EV71)疫苗接种后5年的免疫持久性。方法:在Ⅲ期临床试验免疫原性亚组中，对完成全程两针次免疫的、免前抗EV71中和抗体阴性人群进行免疫后5年采血，并检测抗EV71中和抗体评价免疫持久性。完整检测时间点包括0、56 d和8、14、26、64个月。采用n t检验和卡方检验分析数据。n 结果:疫苗组和安慰剂对照组分别有235和255名受试者具有全部检测点的中和抗体数据。接种后64个月，疫苗组抗EV71中和抗体几何平均滴度(369.57)高于对照组(55.58)，且差异有统计学意义(n t＝14.28，n P<0.01)；分别以抗体滴度8、16、32为阳性判定标准，疫苗组抗体阳性率(100%、99.57%、97.87%)均高于对照组(69.02%、61.96%、59.61%)且差异有统计学意义(n χ2分别为107.93、133.14、130.69，n P值均<0.01)。疫苗接种后其他检测时间点的结果与64个月类似。n 结论:该EV71疫苗两针基础免疫后能够诱导较高的中和抗体水平和阳性率，在免疫后5年依然保持较好的免疫持久性。“,”Objective:To investigate the immunity persistence five-year post vaccination of inactivated enterovirus 71 (EV71) vaccine.Methods:Among the immunogenicity cohort in phase Ⅲ trial, blood samples were collected from a subset of participants having fulfilled 2-dose vaccination protocol, and whose serum EV71 neutralizing antibody (NAb) assay was negative on day 0. NAb was tested to evaluate immunity persistence.The full series of sampling time points included days 0 and 56, as well as months 8, 14, 26, and 64. Data were analyzed by n t-test and chi-square test.n Results:There were 235 subjects in vaccine group and 255 in placebo control group who had full series of sampling points results. At 64-month post vaccination, the geometric mean titer (GMT) of anti-EV71 NAb in vaccine group (369.57) was higher than that in control group (55.58), and the difference was statistically significant (n t=14.28, n P<0.01). By the cutoff NAb titer values of 8, 16, 32, at month 64, the seropositive rates in vaccine group (100%, 99.57%, 97.87%) were higher than those in control group (69.02%, 61.96%, 59.61%), and the differences were statistically significant (chi-square values were 107.93, 133.14, 130.69, respectively; alln P values<0.01). The results at other observed time points post vaccination were similar with those at month 64.n Conclusion:The EV71 vaccine induces a sustained high level of NAb GMTs andseropositive rates against EV71 for at least 5 years.