正常和高应答新生儿乙型肝炎疫苗基础免疫后5年抗体持久性观察

Immune Persistence from Hepatitis B Vaccination among Infants with Normal and High Responses to Primary Immunization: a 5-year Follow-up Study

目的探讨乙型肝炎（乙肝）疫苗（Hep B）正常和高应答新生儿基础免疫后5年抗体持久性及其影响因素。方法选择Hep B基础免疫正常和高应答且未进行加强免疫的新生儿,分别于基础免疫后1～6月和5年采血检测乙肝病毒（HBV）表面抗体（HBs Ab）、HBV核心抗体（HBc Ab）和HBV表面抗原（HBs Ag）,分析HBs Ab抗体水平及影响因素。结果在1 883名新生儿调查对象中,HBs Ab阳性率从Hep B基础免疫后1～6月的100%降至基础免疫后5年的49.92%,几何平均浓度（GMC）从525.62（95%CI：504.65～547.47）m IU/ml降至10.68（95%CI：9.83～11.61）m IU/ml。母亲HBs Ag阳性、阴性、不详的新生儿基础免疫后5年HBs Ab阳性率分别为76.19%、50.29%、47.67%（χ2=6.83,P=0.033）,GMC分别为16.45m IU/ml、10.66m IU/ml、10.52m IU/ml（F=0.59,P=0.553）。多因素分析显示,基础免疫高免疫应答者、母亲HBs Ag阳性者基础免疫后5年HBs Ab阳性率分别高于正常免疫应答者和母亲HBs Ag阴性者。新生儿Hep B基础免疫后5年内HBV突破性感染率为0.85%（16/1 883）,未发现慢性感染者。结论 Hep B基础免疫正常和高应答新生儿在免疫后5年约一半儿童HBs Ab仍处于保护水平,新生儿基础免疫后抗体持久性与其基础免疫后抗体反应水平和母亲HBs Ag感染状态相关。

Objective To assess the persistence of antibody against hepatitis B surface antigen（ HBs Ag）among infants with normal and high responses 5 years after primary immunization with a 3-dose series of hepatitis B vaccine（ Hep B）,and factors influencing antibody persistence. Methods Children with normal or high responses to Hep B primary immunization who had received no booster immunization were chosen as subjects. Blood samples from subjects were collected 1-6 months（ T0） and 5 years（ T1） after primary immunization for testing hepatitis B surface antibody（ HBs Ab）,hepatitis B core antibody（ HBc Ab）,and HBs Ag. HBs Ab levels and factors influencing HBs Ab levels were analyzed. Results Among all 1 883 subjects,the positive rate of HBs Ab decreased from 100% at T0 to 49. 92% at T1,and its geometric mean concentration（ GMC） decreased from 525. 62（ 95% CI： 504. 65-547. 47） to 10. 68（ 95% CI： 9. 83-11. 61） m IU/ml. Among subjects whose mothers were HBs Ag positive,negative and unknown,the respective positive rates of HBs Ab at T1 were 76. 19%,50. 29%,and 47. 67%（ χ2= 6. 83,P = 0. 033）, and the respective GMCs were16. 45,10. 66,and 10. 52 m IU / ml（ F = 0. 59,P = 0. 553）. Multivariable analysis showed that the positivity rate of HBs Ab at T1 among subjects with a high response or whose mothers were HBs Ag positive was greater than among subjects with a low response or whose mothers were HBs Ag negative. Breakthrough hepatitis B virus infections occurred in 0. 85%（ 16 /1883） of subjects,with no chronic infections found. Conclusions About a half of infants with normal and high responses were still immune to hepatitis B 5 years after Hep B primary immunization. Persistence of HBs Ab was associated with high initial HBs Ab levels following primary immunization and with maternal HBs Ag carrier status.