中华流行病学杂志  2015, Vol. 36 Issue (12): 1372-1376   PDF    
http://dx.doi.org/10.3760/cma.j.issn.0254-6450.2015.12.011
中华医学会主办。
0

文章信息

张丽, 颜丙玉, 刘甲野, 吕静静, 冯艺, 徐爱强, 宋立志, 梁晓峰, 李黎, 崔富强, 张国民, 王富珍.
Zhang Li, Yan Bingyu, Liu Jiaye, Lyu Jingjing, Feng Yi, Xu Aiqiang, Song Lizhi, Liang Xiaofeng, Li Li, Cui Fuqiang, Zhang Guomin, Wang Fuzhen.
乙型肝炎疫苗初次免疫正常应答和高应答婴儿初次免疫5年后免疫记忆持久性随访观察
Persistence of immune memory to hepatitis B vaccine among infants with normal or high antibody response to primary vaccination: a five-year following-up study
中华流行病学杂志, 2015, 36(12): 1372-1376
Chinese Journal of Epidemiology, 2015, 36(12): 1372-1376
http://dx.doi.org/10.3760/cma.j.issn.0254-6450.2015.12.011

文章历史

投稿日期: 2015-04-07
乙型肝炎疫苗初次免疫正常应答和高应答婴儿初次免疫5年后免疫记忆持久性随访观察
张丽1 , 颜丙玉1, 刘甲野1, 吕静静1, 冯艺1, 徐爱强1, 宋立志1, 梁晓峰2, 李黎2, 崔富强2, 张国民2, 王富珍2    
1. 250014 济南, 山东省疾病预防控制中心免疫预防管理所 山东省传染病预防控制重点实验室;
2. 中国疾病预防控制中心免疫规划中心
摘要: 目的 探讨乙型肝炎(乙肝)疫苗初次免疫(初免)正常应答和高应答新生儿在初免后5年免疫记忆情况及其影响因素。方法 对初免正常应答和高应答新生儿于初免后5年检测其抗-HBs,其中低于保护水平(10 mIU/ml)者接种1剂次乙肝疫苗(激发剂次)并于接种后14 d采集血标本,再次检测抗-HBs,并计算激发剂次后抗-HBs阳转率(≥10 mIU/ml)和GMT。将检测的初免抗体、随访抗体和激发剂次后抗体均从低到高分成不同等级,分析激发剂次后抗体的影响因素。结果 37.98%(980/2 580)初免正常应答和高应答新生儿在初免后5年抗-HBs已降至保护水平以下,其中激发剂次后98.95%(757/765)出现抗体阳转,GMT为2 811.69(95%CI:2 513.55~3 145.19) mIU/ml。激发剂次后抗体滴度随初免抗体水平和随访抗体水平的升高而升高(F值分别为5.46、10.23,均P<0.000 1)。多因素分析显示,激发剂次后抗体滴度与性别、出生体重、早产等无关(P>0.05),而与初免抗体和随访抗体水平独立相关(OR=1.001,95%CI:1.000~1.002,P<0.001;OR=1.28,95%CI:1.81~1.39,P<0.001)。结论 新生儿乙肝疫苗初免后5年存在较强的免疫记忆;免疫记忆的强度与初免抗体及激发剂次前抗体水平有关。
关键词: 肝炎疫苗,乙型    婴儿    免疫记忆    持久性    
Persistence of immune memory to hepatitis B vaccine among infants with normal or high antibody response to primary vaccination: a five-year following-up study
Zhang Li , Yan Bingyu, Liu Jiaye, Lyu Jingjing, Feng Yi, Xu Aiqiang, Song Lizhi, Liang Xiaofeng, Li Li, Cui Fuqiang, Zhang Guomin, Wang Fuzhen    
1. Expanded Program Immunization Division of Shandong Provincial Center for Disease Control and Prevention, Shandong Provincial Key Laboratory of Infectious Disease Control and Prevention, Jinan 250014, China;
2. National Immunization Program, Chinese Center for Disease Control and Prevention
Abstract: Objective To examine the immune memory status to hepatitis B vaccine among infants with normal or high antibody response to primary vaccination, 5 years after the primary vaccination and the risk factors associated with the immune memory. Methods Titers of the antibody against hepatitis B surface antigen (anti-HBs) were detected, five years after the primary vaccination among children who appeared normal or high response to hepatitis B primary vaccination in infancy. Those whose anti-HBs titers were low than protective level (10 mIU/ml) were given a challenge dose of hepatitis B vaccine and titers of anti-HBs were detected 14 days after the challenge. Positive rate and geometric mean titer (GMT) of anti-HBs were calculated. Level of the anti-HBs titers after primary vaccination,at following-up and after the challenge periods were divided into different levels, respectively. Risk factors associated with the levels of anti-HBs titer after the challenge were examined by univariate analysis that and multivariable analysis. Results Anti-HBs waned to the level below protective standard among 37.98% of the children with normal or high antibody response to hepatitis B primary vaccination; among those children whose anti-HBs were below the protection standard. The seroconversion rate and GMT of anti-HBs after the challenge dose were 98.95%(757/765) and 2 811.69 mIU/ml [95% Confidence Interval(CI):2 513.55-3 145.19 mIU/ml], respectively. Titers and levels of anti-HBs after the challenge, appeared an increase with anti-HBs after primary vaccination and the anti-HBs in the following-up (F=5.46,10.23 respectively; P<0.000 1 for both) periods. Results from the multivariable analysis showed that gender, premature birth and birth weight were factors insignificantly associated with the anti-HBs titers after the dose of challenge, while the anti-HBs levels were independently associated with the levels of anti-HBs titer after the challenge [OR=1.001(95%CI:1.000-1.002),P<0.001;OR=1.28(95%CI:1.81-1.39),P<0.001] at the following-up periods. Conclusions Strong immune memory could be found among those children with normal or high responses to hepatitis B vaccination, 5 years after the primary vaccination. The intensity of immune memory might be associated with the anti-HBs titer after primary vaccination as well as the anti-HBs titers before the challenge dose was given.
Key words: Hepatitis B vaccine    Infants    Immune memory    Persistence    

新生儿接种乙型肝炎(乙肝)疫苗是预防HBV感染的有效措施,且接种后保护性抗体可持续多年,即使抗-HBs降低到保护性水平(10 mIU/ml)以下,免疫记忆仍可使机体在暴露于HBV后快速产生免疫反应,起到抵御感染的作用[1, 2, 3, 4, 5, 6, 7, 8, 9]。目前关于新生儿乙肝疫苗初次免疫(初免)后不同时间免疫记忆持久性的研究,多数未提供研究对象的人口学特征及初免后的抗体反应情况[3, 5, 6, 7, 8, 9],无法分析免疫记忆持久性的相关因素。为此本研究开展了新生儿初免抗体应答观察,并随访其中初免正常应答和高应答者,评估随访抗体水平低于保护水平者的免疫记忆情况。

对象与方法

1. 研究对象: 2009年8-9月在山东省10个县(市、区)选择按照“0-1-6”程序完成3剂次5 μg重组乙肝疫苗(啤酒酵母)初免的7~12月龄儿童,采集静脉血2 ml,经检测抗-HBs≥100 mIU/ml者,于2014年5-6月(约初免后5年)再次采集静脉血检测抗-HBs,抗-HBs<10 mIU/ml且初免后未进行加强免疫接种者列为研究对象。其中乙肝疫苗接种史通过查阅预防接种证明获得。本研究经山东省疾病预防控制中心预防医学伦理委员会批准,所有研究对象监护人均签署知情同意书。

2. 调查内容及方法:在新生儿初免抗体应答观察时,由经过培训的调查人员通过询问儿童监护人获得包括初免抗体检测月龄、性别、出生体重、是否早产、母亲HBsAg情况等。以激发剂次乙肝疫苗的免疫回忆反应评价乙肝疫苗免疫记忆[5, 6, 7, 8, 9]。即对所有研究对象接种1剂次(激发剂次)乙肝疫苗(每剂次10 μg,辽宁省大连汉信生物制药有限公司产品;批号:201304070),并于接种14 d后采集静脉血3~5 ml。所有疫苗均由中国食品药品检定所批签发,本研究组统一采购并按照说明书冷链配发至接种地点。采用化学发光微粒子免疫分析法(chemiluminescence microparticle imunoassay,CMIA)定量检测抗-HBs(采用美国雅培公司试剂及该公司ARCHITECT?i2000型全自动发光检测仪器);检测值>标准曲线上限(1 000 mIU/ml)者15倍稀释后测定。检测委托第三方医学检验公司完成。

3. 相关定义:本研究中早产为28~37孕周分娩;抗-HBs阳转为抗-HBs滴度由<10 mIU/ml升高为≥10 mIU/ml;无应答为免后抗-HBs<10 mIU/ml;低应答为免后10 mIU/ml≤抗-HBs<100 mIU/ml;正常应答为免后100 mIU/ml≤抗-HBs<1 000 mIU/ml;高应答为免后抗-HBs≥1 000 mIU/ml[10]

4. 统计学分析:采用EpiData数据库进行数据双录入和比对,双录入不符者对照原始调查表进行核对和修订;采用Stata 10.0软件进行统计学分析,其中分类资料的单因素分析采用Spearman χ2或Fisher’s精确概率法,计量资料单因素分析采用t检验或单因素方差分析,等级资料的单因素和多因素分析采用有序结果的累积比数logistic回归分析[11]。结果判定中,P值取双侧概率,检验水准α=0.05。

结果

1. 基本情况:共对4 147名儿童检测初免后抗-HBs,其中无应答、低应答、正常应答和高应答分别为83人(2.00%)、717人(17.29%)、2 641人(63.68%)和706人(17.02%)。共随访到2 580名初免正常应答和高应答儿童,其中抗-HBs低于保护水平者980人(37.98%),其中765人(78.06%)完成了免疫记忆评价(激发剂次乙肝疫苗接种和接种后抗体检测)。完成和未完成免疫记忆评价者初免抗体检测时月龄、性别、出生体重、早产和母亲HBsAg、初免抗体水平和随访抗体等构成的差异均无统计学意义(P值分别为0.44、0.35、0.46、0.73、0.54、0.56和0.22)。见表1

表 1 完成和未完成免疫记忆评价者基本特征比较

2. 激发剂次后检测:

(1)抗-HBs水平:激发剂次后所有研究对象中抗-HBs阳转率为98.95%(757/765),其中无应答率、低应答率、正常应答率和高应答率分别为1.05%(8/765)、1.31%(10/765)、19.22%(147/765)和78.43%(600/765)。初免正常应答抗体阳转率(98.83%,678/686)低于高应答者(100.00%,79/79),但差异无统计学意义(Fisher’s 精确概率法,P=1.000)。激发剂次后抗体GMT为2 811.69 (95%CI:2 513.55~3 145.19) mIU/ml,其中初免正常应答和高应答者分别为2 665.73(95%CI:2 356.83~3 015.12) mIU/ml和4 213.90(95%CI:3 099.44~5 729.07) mIU/ml,差异有统计学意义(t=2.38,P=0.02)。将初免抗体水平由低到高分成10个等级,激发剂次后抗体由低到高分为4个等级,不同初免抗体等级者激发剂次后阳转率的差异无统计学意义(Pearson χ2=6.8,P=0.74),但随着初免抗体等级的升高,激发剂次抗体滴度和等级亦升高(F=5.46,P<0.000 1;χ2=3.37,P=0.004)。见表2

表 2 乙肝疫苗初免不同抗体水平儿童激发剂次后抗体反应

将随访(激发剂次前)抗体水平分为由低到高10个等级。不同随访抗体水平间激发剂次后抗体阳转率的差异无统计学意义(χ2=9.48,P=0.39),但激发剂次后抗体GMT和激发抗体水平等级均随着随访抗体等级的增加而升高(F=10.23,P<0.000 1;χ2=57.15,P<0.000 1)。见表3

表 3 乙肝疫苗初次免疫后5年随访不同抗体水平儿童激发剂次后抗体反应

(2)影响抗体水平的因素:将初免检测时月龄、性别、出生体重、早产、抗-HBs水平(初免和随访)作为自变量(变量分级见表1),激发剂次后抗体水平作为因变量(变量分级见表2)。多因素分析显示,初免抗体检测时月龄、性别、早产、出生体重与激发剂次后抗体水平无关(P>0.05);而初免和随访抗-HBs水平与激发剂次后抗-HBs水平显著相关,其中初免抗-HBs水平每升高一个等级,激发剂次后抗体升高一个等级的可能性将增加1.001倍(OR=1.001,95%CI:1.000~1.002,P<0.01); 随访时抗-HBs水平每升高一个等级,激发剂次后抗体升高一个等级的可能性将增加1.28倍(OR=1.28,95%CI:1.18~1.39,P<0.001)。见表4

表 4 新生儿初免正常应答和高应答者激发剂次后影响抗体水平的因素
讨论

乙肝疫苗接种后的免疫记忆持久性是评价疫苗免疫效果的重要指标,也是判断初免后是否需要加强免疫及何时进行加强免疫的主要依据之一。抗-HBs是HBV自然感染或乙肝疫苗接种后产生的保护性抗体。根据接种后抗-HBs水平,可将抗体反应分为无应答、低应答、正常应答和高应答[10]。既往研究发现,乙肝疫苗接种后抗-HBs≥100 mIU/ml者可以获得长久的免疫保护[12]。本研究对初免抗-HBs≥100 mIU/ml即正常应答和高应答的新生儿进行5年随访,发现随访时近40%已降至保护水平之下,但98.95%在接种激发剂次乙肝疫苗14 d内出现了抗-HBs阳转,且GMT高达2 811.69 mIU/ml,说明绝大多数儿童在初免后5年有良好的免疫记忆。本研究中激发剂次乙肝疫苗的HBsAg量较低(10 μg/0.5 ml)。HBV感染机体后,潜伏期为45~160 d,平均90 d,极少数可短至2周[13]。而本研究激发剂次后2周时绝大多数接种对象抗-HBs已高于保护水平。说明新生儿乙肝疫苗初免后5年,即使抗体降至保护水平之下,仍可通过免疫记忆获得有效的免疫保护,无需加强免疫,与既往研究结果一致[5, 6, 7, 8, 9]。本研究中,激发剂次后的抗体阳转率和抗体水平均明显高于其他随访时间更长的研究[5, 6, 7, 8, 9],也证明了新生儿接种乙肝疫苗的免疫记忆会随接种时间的延长而减弱。

本次是在乙肝疫苗初免基础上开展的随访研究。结果显示,新生儿初免抗体水平与激发剂次后抗体水平独立相关,提示今后在评价免疫记忆持久性及制定加强免疫策略时应考虑儿童初免抗体应答情况。研究中未发现初免抗体水平与激发剂次后抗体阳转率显著相关,可能与本研究的随访时间与初免时间间隔较短,激发剂次后抗体阳转率总体很高有关;延长随访时间可能会得到更准确的结论。意大利一项研究认为,激发剂次前抗体>2 mIU/ml者可以保证激发剂次后获得足够的抗体反应[14];美国一项研究则认为婴儿期完成3剂次乙肝疫苗接种16~19年后,如果可检出残留抗体(非零),则意味着存在对HBsAg的免疫记忆[15];而我国一项研究则将存在免疫记忆的残存抗体水平定为1.0 mIU/ml[9]。本研究亦发现随访抗体水平与激发剂次后抗体水平独立相关,与以上研究结论一致。研究中未发现性别、出生体重、早产等因素与免疫记忆持久性有关;与Middleman等[7]的研究结果一致。

本研究随访时间与初免时间间隔较短,故难以有效评价新生儿乙肝疫苗全程免疫后免疫记忆长期持久性;研究中新生儿初免抗体采血时间跨度较大(全程免疫后1~6个月),可能影响初免抗体水平检测结果;此外研究对象出生信息是通过询问监护人获得,可能出现信息的回忆偏移。尽管如此,本研究提示婴儿期乙肝疫苗初免正常应答和高应答者,在初免后5年仍有较强的免疫记忆;免疫记忆的强度与初免抗体水平和激发剂次前抗体水平有关。

(感谢章丘市、寿光市、烟台市和威海市疾病预防控制中心相关人员在数据收集过程中给予的大力帮助)

参考文献
[1] Poovorawan Y,Chongsrisawat V,Theamboonlers A,et al. Persistence and immune memory to hepatitis B vaccine 20 years after primary vaccination of Thai infants,born to HBsAg and HBeAg positive mothers[J]. Hum Vaccin Immunother,2012,8(7):896-904.
[2] Zhai RF,Xing XS,Wang HJ,et al. To observe the antibody persistence of recombinant yeast derived hepatitis B vaccine(YDV) after 12 years immunization[J]. Chin J Vaccine Immunizat,2008,14(6):521-523. (in Chinese) 翟如芳,邢秀生,王海娇,等. 重组乙型肝炎疫苗(酵母)免疫后12 年的抗体持久性研究[J]. 中国疫苗和免疫,2008,14(6):521-523.
[3] Poovorawan Y,Chongsrisawat V,Theamboonlers A,et al. Long-term anti-HBs antibody persistence following infant vaccination against hepatitis B and evaluation of anamnestic response:a 20-year follow-up study in Thailand[J]. Hum Vaccin Immunother,2013,9(8):1679-1684.
[4] Tohme RA,Awosika-Olumo D,Nielsen C,et al. Evaluation of hepatitis B vaccine immunogenicity among older adults during an outbreak response in assisted living facilities[J]. Vaccine,2011,29(50):9316-9320.
[5] Spradling PR,Xing J,Williams R,et al. Immunity to hepatitis B virus infection two decades after implementation of universal infant hepatitis B vaccine:the association of detectable residual antibody and response to a single hepatitis B vaccine challenge dose[J]. Clin Vaccine Immunol,2013,20(4):559-561.
[6] Banatvala J,van Damme P,Oehen S. Lifelong protection against hepatitis B:the role of vaccine immunogenicity in immune memory[J]. Vaccine,2000,19(7/8):877-885.
[7] Middleman AB,Baker CJ,Kozinetz CA,et al. Duration of protection after infant hepatitis B vaccination series[J]. Pediatrics,2014,133(6):e1500-e1507.
[8] Xia GL,Bai Y,Liu KZ,et al. Long-term immunological memory after hepatitis B vaccination[J]. Chin J Vaccine Immunizat,2002,8(2):61-64. (in Chinese) 夏国良,白玉,刘克洲,等. 乙型肝炎疫苗免疫后免疫回忆应答的观察[J]. 中国计划免疫,2002,8(2):61-64.
[9] Yao J,Shan H,Chen Y,et al. The one year effects of three doses of hepatitis b vaccine as a booster in anti-HBs-negative children 11-15 years after primary immunization; China,2009-2011[J]. Hum Vaccin Immunother,2015,11(5):1114-1119.
[10] Isolani AP,Sversuti CS,Sell AM,et al. Protection against hepatitis B by the Butang recombinant vaccine in newborn children in South Brazil[J]. Mem Inst Oswaldo Cruz,2006,101(5):551-553.
[11] Chen F. Modern medicine statistical method and the application of Stata[M]. 2nd ed. Beijing:Chinese Statistics Press,2003:200-203. (in Chinese) 陈峰. 现代医学统计方法与Stata应用[M]. 2版. 北京:中国统计出版社,2003:200-203.
[12] Clemens R,Sänger R,Kruppenbacher J,et al. Booster immunization of low-and non-responders after a standard three dose hepatitis B vaccine schedule-results of a post-marketing surveillance[J]. Vaccine,1997,15(4):349-352.
[13] Luo KX. Hepatitis B basic biology and clinical science[M]. 3rd ed. Beijing:People's Medical Publishing House,2006:409. (in Chinese) 骆抗先. 乙型肝炎基础和临床[M]. 3版. 北京:人民卫生出版社,2006:409.
[14] Chiara F,Bartolucci GB,Cattai M,et al. Hepatitis B vaccination of adolescents:Significance of non-protective antibodies[J]. Vaccine,2013,32(1):62-68.
[15] Spradling PR,Kamili S,Xing J,et al. Response to challenge dose among young adults vaccinated for hepatitis B as infants:importance of detectable residual antibody to hepatitis B surface antigen[J]. Infect Control Hosp Epidemiol,2015,36(5):529-533.