目的:探讨免疫前抗体水平对流感疫苗血清阳转率的影响。方法:2009年9月—2018年10月在新疆维吾尔自治区和云南省共招募1 900例健康志愿者接种流感病毒裂解疫苗，采集疫苗接种前和接种后28 d的血液样本，使用血凝素凝集抑制试验测定血清疫苗组分抗体滴度，分析免疫前抗体水平对不同疫苗组分血清阳转率的影响。结果:趋势性分析表明，随着免疫前抗体滴度的增加，A/H1N1、A/H3N2、B/Victoria和B/Yamagata疫苗组分的血清阳转率逐渐减小(χn 2＝121.76，n P<0.001；χn 2＝67.58，n P<0.001；χn 2＝45.25，n P<0.001；χn 2＝54.55，n P<0.001)。多因素分析显示，调整了地区、性别和年龄因素后，免疫前抗体滴度≥40是A/H1N1、A/H3N2和B/Victoria疫苗组分血清阳转的独立影响因素，其调整OR(95%CI)值分别为2.50(2.00～3.13)、1.64(1.35～2.00)和2.50(1.79～3.45)。n 结论:各个疫苗组分血清阳转率与免疫前抗体滴度呈负相关。免疫前抗体滴度≥40是A/H1N1、A/H3N2和B/Victoria疫苗组分血清阳转的不利因素，尚未发现此因素对B/Yamagata疫苗组分血清阳转有影响。“,”Objective:To investigate the effects of pre-existing antibody on seroconversion rate after influenza vaccination.Methods:This study recruited 1 900 healthy volunteers to receive influenza split vaccines in Xinjiang Uygur Autonomous region and Yunnan Province from September 2009 to October 2018. Hemagglutinin agglutination inhibition assay was used to detect the titers of specific antibodies in blood samples collected before vaccination and 28 d after vaccination and the effects of pre-existing antibody on the seroconversion to different influenza vaccine components were analyzed.Results:Trend analysis showed that with the increasing titer of pre-existing antibody, the seroconversion rates to A/H1N1, A/H3N2, B/Victoria and B/Yamagata vaccine components were gradually decreased (χn 2=121.76, n P<0.001; χn 2=67.58, n P<0.001; χn 2=45.25, n P<0.001; χn 2=54.55, n P<0.001). After adjusting for factors such as region, gender and age, multivariate logistic regression showed that pre-existing antibody titer equal to or higher than 40 was an independent factor that affected the seroconversion to A/H1N1, A/H3N2 and B/Victoria vaccine components, and the adjusted OR (95%CI) values were 2.50(2.00-3.13)、1.64(1.35-2.00) and 2.50(1.79-3.45), respectively.n Conclusions:The seroconversion rate to each vaccine component was negatively correlated with the pre-existing antibody titer. The factor that pre-existing antibody titer equal to or higher than 40 was detrimental to the seroconversion to A/H1N1, A/H3N2 and B/Victoria vaccine components, but had no significant influence on B/Yamagata seroconversion.