中山市健康人群乙肝血清学监测情况分析

目的 了解乙肝疫苗接种效果情况，进而探讨如何更好地实行免费接种乙肝疫苗，确保接种质量。方法 随机抽取152名新生儿和1岁以上健康人群2495名，应用酶联免疫法对其血清进行HBsAg和anti．HBsAg检测。结果 152名新生儿，抗-HBs阳性141人，阳性率为92．7％。HBsAg阳性0人。2495名1岁以上健康人群，抗-HBs阳性1199人，阳性率为48．1％，HBsAg阳性259人，阳性率为10．4％。1～18岁844人，HBsAg阳性10人，阳性率为1．2％。18岁以上1651人，HBsAg阳性249人，阳性率为15．1％。结论 对新生儿及时进行乙肝疫苗全程免疫，能提高新生儿对乙肝的免疫力，预防乙肝。接种乙肝疫苗、提高接种质量能提高易感人群对乙肝的免疫力。降低人群乙肝感染率。1岁以上健康人群抗-HBs阳性率偏低，存在感染乙型肝炎病毒的危险。     

重组酵母乙肝疫苗对新生儿免疫效果的评价

目的研究新生儿接种国产5μg重组酵母乙肝疫苗的免疫效果及影响因素。方法从东莞市石碣医院预防接种门诊登记的,2005年7～12月出生的,按规定接种程序完成乙肝疫苗接种的新生儿中随机抽取303名进行横断面调查研究。结果新生儿免疫后抗-HBs几何平均滴度（GMT）为（201.36±14.89）mIU/ml。母亲乙肝HBsAg阳性/阴性、母亲乙肝HBeAg阳性/阴性、男/女、是否出生低体重、是否早产、本地/外地的新生儿之间抗-HBs抗体GMT差别无统计学意义（P〉0.05）。抗-HBs阳转率为97.69%,达到卫生部规定的免疫成功率指标（85%）（t=6.19,P〈0.001）;母亲HBsAg阳性/阴性、HBeAg阳性/阴性的新生儿之间抗-HBs阳转率差别有统计学意义。新生儿HBsAg阳性率0.33%,母亲乙肝HBeAg阳性/阴性的新生儿HBsAg阳性率差别有统计学意义（P〈0.05）。免疫后母婴传播阻断保护率为96.16%。结论新生儿接种国产5μg重组酵母乙肝疫苗具有良好的免疫效果,与乙肝免疫球蛋白100 IU联合使用,有良好的母婴传播阻断保护作用。母亲乙肝感染状况（HBsAg、HBeAg阳性）是影响新生儿乙肝抗-HBs阳转率的危险因素;母亲乙肝HBeAg阳性是影响新生儿乙肝疫苗母婴传播阻断保护率的危险因素。     

成都双流机场职工接种乙肝疫苗的效果分析

目的:了解机场职工接种乙肝疫苗以后产生抗-HBs情况,观察乙肝疫苗免疫接种效果,探讨注射乙肝疫苗后不同年龄、不同性别之间抗-HBs阳性率的差异。方法:将2006～2008年度机场职工年度体检所检测的抗-HBs资料结合同期接受乙肝疫苗预防注射的档案进行回顾性研究,比较接种乙肝疫苗前后抗-HBs的差异。结果:研究对象276人。经预防接种乙肝疫苗以后,抗-HBs阳性率为79.2%,接种后抗-HBs阳性率明显高于未接种者(x2=26.857p=0.000),具有统计学意义。结论:接种乙肝疫苗是目前预防乙型肝炎的最有效措施,实施乙肝疫苗接种,对于基层单位做好职工的预防保健工作中具有十分重要的意义。     

乙型肝炎疫苗高覆盖率对接种人群发病的影响

目的 评价乙型肝炎(乙肝)疫苗高免疫覆盖率的免疫效果.方法 收集接种人群历年的接种报告、乙肝血清学流行率调查结果,分析乙肝疫苗接种后历年乙肝发病的疫情报告,采用酶联免疫吸附试验测定乙肝表面抗原、乙肝表面抗体和乙肝核心抗体,并与接种前期的检测结果进行比较.结果 1992—2011年(乙肝疫苗接种20年)烟台市15岁以下儿童乙肝发病下降了86.84%.5~14岁发病高峰被削平.全人群乙肝表面抗原携带率从1990年13.59%,降至2006年4.61%,从乙肝高度流行区降到了中度流行区.同期0~15岁乙肝表面抗原携带率由12.67%降至0.82%,降幅达到93.53%.结论 乙肝疫苗高覆盖率接种有显著的免疫保护效果,应继续坚持.     

广州市应用乙型肝炎疫苗免疫22年人群血清学效果研究

目的评价广州市长期应用乙型肝炎疫苗（hepatitis B vaccine,HepB）对乙型肝炎（乙肝）免疫防病效果。方法在广州市全市12个区、县级市按照多阶段分层整群抽样法,以家庭为单位对1～59岁人群进行横断面调查分析,包括检测HBsAg、抗-HBs,对HepB接种史及主要乙肝感染危险因素进行问卷调查,评估人群HepB接种率,分析和比较不同年龄组、不同家庭感染状况下接种与未接种HepB人群乙型肝炎病毒感染指标,评价HepB免疫防病效果。结果 1～16岁年龄组乙肝疫苗全程接种率为88.11%（2535/2877）,17～59岁人群有乙肝疫苗免疫史为20.75%（470/2113）。在推行新生儿HepB接种纳入计划免疫管理后出生的1～16岁人群,HBsAg阳性率为1.29%,而出生时尚未开展HepB接种的20～59岁人群HBsAg阳性率为13.72%。1～16岁人群中有HepB接种史人群HBsAg阳性率0.99%,无接种史人群为5.56%,疫苗保护率为82.19%。20～59岁人群接种HepB,基本都不是在新生儿时期,疫苗保护率为52.01%。新生儿接种HepB,母婴乙肝传播阻断率为94.16%,并能有效阻断家庭内水平传播。结论长期实施新生儿接种HepB能控制、消除受种人群乙肝病毒感染,非新生儿人群接种HepB也能显著降低乙肝病毒感染率。     

幼儿园儿童接种乙肝疫苗的免疫效果观察

为了解我园幼儿接种乙肝疫苗的效果,进一步搞好乙肝防治工作,2000年3月对接种乙肝疫苗的376例儿童检测了抗-HBs水平,报道如下. 1 对象选择广钢幼儿园小班、中班、大班出生时已严格按0、1、6程序全程接种乙肝疫苗的儿童376名.所有受试者取静脉血 3ml,用酶联免疫吸附法检测血中的乙型肝炎表面抗体.试剂由上海实业科华生物有限公司出品.操作过程及结果判定严格按试剂说明书进行. 2 结果 376中抗-HBs阳性者 295人(78.5%).小班阳性最高为104例(83.9)%.中班阳性100例(82.6%).大班阳性91例(69.5%). 3 讨论乙型肝炎疫苗广泛用于我国婴幼儿等易感人群.众所周知,乙型肝炎难以治愈,而且可能发展为肝硬化,甚至肝癌.从上结果看,接种乙肝疫苗后抗-HBs阳性率随着全程免疫接种后的时间推移逐渐降低.在初免后60个月,抗-HBs低滴度构成较高,是加强免疫的最好时间［1］.所以在初免后4～5年应再加强免疫.建议入托新生常规检查乙肝表面抗原和表面抗体.对HbsAg阴性,而抗-HBs阳性的婴幼儿不接种乙肝疫苗.对HbsAg阳性者不准入托.而HbsAg和抗-HBs阴性者作为乙肝疫苗的接种对象.这样做既防止了乙肝在幼儿园内的交叉感染,又使婴幼儿体内形成足够的抗体,防止乙型肝炎的发生.     

山东某高校大学新生乙型肝炎病毒感染及免疫分析CSCD

目的 研究大学生乙肝疫苗接种率及HBsAg、抗-HBs检出率,为大学新生乙肝防治工作提供依据.方法 以某高校2016年新入学的大学生为研究对象,发放调查问卷;采用酶联免疫吸附法（ELISA）检测血清中HBsAg和抗-HBs.结果 728名研究对象乙肝疫苗接种率80.8％,城市高于农村（P ＜0.005）.HBsAg阳性率为3.4％,城市、农村差异无统计学意义.抗-HBs阳性率为65.2％,城市高于农村（P＜0.05）.有接种史者抗-HBs阳性率明显高于无接种史者（P ＜0.005）,以上各组性别差异均无统计学意义.结论 结合大学新生接种史和HBsAg、抗-HBs检测结果,进行乙肝疫苗加强;同时,应加强农村地区预防接种工作.     

四川省遂宁市2009年乙型病毒性肝炎血清流行病学调查

目的 了解四川遂宁市乙肝病毒感染状况,评价遂宁市从1992年在新生儿中推广乙肝疫苗免疫策略的效果.方法 采用多阶段分层随机抽样的方法,按行政区域和经济水平随机抽取6个调查点（村、县）,以家庭为单位对全部人群采集外周静脉血,用酶联免疫吸附实验法（ELISA）检测HBsAg、抗-HBs、和抗-HBc.结果 共采集1468人血清进行检测,人群中HBsAg阳性率为14.78%、抗-HBs阳性率为39.17%、HBV感染率72.68%.HBsAg阳性率最高年龄组为30～34岁组（27.59%）,最低为0～4岁组（2.06%）;HBV感染率最高的是55～59岁组（93.13%）,最低是5～9岁组（44.2%）;性别、年龄、职业、地域HBV感染标志流行率均存在差异.结论 四川遂宁地区人群HBV感染率较高,人群HBsAg阳性率仍高于全国平均水平,但人群中乙肝流行病学特征已经发生了改变,乙肝疫苗的接种推广使用,已经显著降低了目标人群（≤14岁人群）的HBsAg阳性率和HBV感染率.     

宋楼镇儿童乙肝疫苗接种效果调查分析

目的：调查分析宋楼镇儿童乙肝疫苗接种的效果情况。方法2013年5月对宋楼镇幼儿园在园内的2~6岁学龄前儿童共562例分为2~岁、3~岁、4~岁、5~岁和6岁共5个组，进行乙肝疫苗接种效果调查。空腹抽取静脉血3皂l分离血清备用，以酶联免疫法(ELISA)来测定乙肝表面抗原(HBsAg)和表面抗体(抗-HBs)。结果表面抗体阳性率最高为2~岁年龄组，达到90.54%；最低的为6岁年龄组，达到82.67%。伴随着儿童年龄的增长，儿童的表面抗体率在2~6岁呈现一个下降的趋势，并且显示在各年龄组阳性率卡方趋势的检验结果，存在明显差异，具有统计学意义(字2=22.41，<0.05)。结论可当儿童于3~4岁时做一次免疫加强接种乙肝疫苗，由此可促进疫苗的免疫保护效果的提高。     

乙型肝炎疫苗接种者免疫应答状况分析

<正>目前乙肝疫苗接种重点是新生儿、血液制品使用者及与传染源密切接触的人群,但对一般人群的应用价值尚需进一步研究.我们对乙肝疫苗接种者的免疫应答状况及有关因素进行了分析,报告如下:1 材料和方法1.1 接种对象 5项乙肝血清学指标全部阴性者有203人,其中男性142人,女性61人.年龄21-60岁,平均年龄42.5岁.1.2 接种方法 分每人70μg和每人90μg两种剂量组.前者按30—30—10μg,后者按30—30—30μg分三次上臂三角肌注射.两组均按0—1—6月免疫程序接种.疫苗为卫生部上海生物制品研究所产品.1.3 抗HBs抗体测定 疫苗第三针接种后三个月采血分离血清,采用上海实业科华生物技术有限公司产品作ELISA检测,以抗HBs阳性率反映抗体应答能力.2 结果2.1 乙肝疫苗接种者的免疫应答 如表1所示,203例成人乙肝疫苗接种后产生抗HBs者140例,总应答率达(69.0%).男性应答率(70.4%)与女性(65.5%)无明显差异(P>0.05).按不同年龄组分析,发现随年龄增长,应答能力逐渐减弱;年龄与应     

Distribution of anti-HBs levels in Korean adults

Exact titration of anti-HBs with mIU/mL unit is necessary in evaluating the success of HBV vaccination or in making a decision to increase the dose of HBV vaccination. Data of distribution of anti-HBs titers can contribute to cutting of public health costs by reducing unnecessary HBV booster doses. Moreover, anti-HBc is also an important marker for differentiation of vaccination-induced anti-HBs from infection-acquired anti-HBs. However, not much study about these subjects has been done in Korea. So we evaluated anti-HBs associated with anti-HBc and vaccination history. HBsAg and anti-HBs tests were done in 1,465 cases. The positive rates of HBsAg and anti-HBs were 4.5% and 74.6%, respectively. Anti-HBs positive rate was higher in the vaccinated group than that in the non-vaccinated group. The rates of anti-HBs positive cases with lower titers (10-< 100 mIU/mL) were 31.9%, while cases with higher titers (> or = 100 mIU/mL) were 68.1%. This suggested about 70% of anti-HBs-positive Korean adults (about 53% of the general adult population) have long-lasting immunity against HBV infection and may not require booster doses of HBV vaccination for a long time. Anti-HBs titers in the vaccine-induced anti-HBs group were higher than those in the infection-acquired anti-HBs group. No statistical differences were noted between male and female or among age groups. 25.7% of the HBsAg (-)/anti-HBs (-) group showed anti-HBc positive and HBV-DNA was detected in 11.1% among HBsAg (-)/anti-HBs (-)/anti-HBcAb (+) cases. Further study about post vaccination anti-HBs titer decay in Korean should be performed to help cut vaccination costs.     

Hepatitis B vaccination status in an at-risk adult population: long-term immunity but insufficient coverage

In France, hepatitis B (HB) vaccine has been offered to all infants since 1994, and was proposed to all children aged 11 years from 1994 to 1998. Nevertheless, HB vaccine hesitancy may result in low vaccination coverage in present-day at-risk adults. We aimed to determine HB vaccination coverage in adults attending a free testing center for sexually transmitted infections (STI). As part of routine care, three classes of data were anonymously collected from attendees over a 3-month period: results of HB serologic tests; date and number of past anti-hepatitis B virus (HBV) immunization(s) (if any) according to health records; and the risk of STI and blood-transmitted infections (BTI). The study included 735 participants (age 27.9?±?9.2; 59.9% men). According to available health records (341 participants), 56.6% had received at least three and 67.2% at least one vaccine injection(s); 57.7% had received their last injection between 1994 and 1998, reflecting the strong vaccine policy during these years. Serologic testing (in 705 participants) showed evidence of a past or active HBV infection for 33 participants; of the remaining patients, 55.3% had anti-HBs antibody titers ≥10 IU/L. This rate was not higher in participants considered at risk for STI/BTI. Of the participants who received their last vaccine injection more than 15 years previously, 90.5% had anti-HBs antibody concentrations ≥10 and 60.3% ≥100 IU/mL. HB vaccination coverage is low in this population. Most of the vaccinated participants were immunized between 1994 and 1998, suggesting a failure of catch-up immunization of adolescents and at-risk adults. Long-term seroprotection persisted among vaccinated participants.     

Hepatitis B vaccination of immunosuppressed heart transplant recipients with the vaccine Hepa Gene 3 containing pre-S1, pre-S2, and S gene products

The antibody response of immunosuppressed heart transplant recipients to vaccination with the hepatitis B (HB) virus vaccine Hepa Gene 3 (HG-3), containing HB virus pre-S1, pre-S2, and S gene products, was examined. Three heart transplant recipients who had been vaccinated preoperatively against HB responded well to the vaccination. Five of 38 patients (13.2%) vaccinated postoperatively before HG-3 vaccination with the second-generation vaccine Gen-H-B-Vax-D (37 without and 1 with detectable anti-HBs response) and 3 of 24 (12.5%) without previous HB vaccination developed protective anti-HBs titers (greater than 10 U/1) after immunization with the HG-3 vaccine. The l low response rate (8/62, 12.9%) found for postoperatively vaccinated patients indicates that heart transplant recipients should be vaccinated against HB before immunosuppressive medication.Abbreviations HB hepatitis B - HG-3 Hepa gene 3     

Immunogenicity of a five-microgram dose of hepatitis B vaccine

The immunogenicity of a 5-μg dose of vaccine (H-B-Vax, MSD) was evaluated in 50 young adults (17–19 years). Results were compared to our previous studies using similarly prepared vaccines using 20 μg and 10 μg per dose with the same trial protocol in a comparable population. Seroconversion rates for the 5-μg doses of vaccine were 80% after the first dose and 98% after the second dose. The remaining participants did not develop anti-HBs in the course of the trial. These results are not significantly different from those observed in the 10-μg and 20-μg studies. The increase of anti-HBs titers was slower for the 5-μg group. High geometric mean titers were observed after booster vaccination, but lower for the 5μg (3,591 mIU/ml) than for 10 μg (9,277 mIU/ml) and 20 μg (12,975mIU/ml) doses. It is concluded that 5-μg dose of the vaccine is effectively immunogenic for young adults.     

Efficacy of hepatitis B virus (HBV) vaccine in long term prevention of HBV infection

Efficacy of HBV vaccine in long term prevention of HBV infection was evaluated at 3 years after vaccination in 38 children and 61 adults. All vaccinees were negative for all HBV markers (HBsAg, anti-HBs and anti-HBc) before vaccination. Vaccines (Hevac B) were given for 3 doses, one month apart, to 38 children aged 1 month - 14 years and 61 adults aged 15-45 years. After 3 years of vaccination, blood specimens were collected for the determination of HBsAg, anti-HBs and anti-HBc. The results revealed that no HBsAg antigenemia was found in all 99 vaccinees. Anti-HBs could not be detected in 4 children and 11 adults and this occurred only in the group of subjects who had initial anti-HBs less than 100 mlU/ml at 2 months after the last dose of vaccination. At three years after the first course of vaccination, 89.4 percent of children and 83.4 percent of adults still have anti-HBs above protective level (more than 10 mlU/ml) with geometric mean titers of 101 and 35 mlU/ml in children and in adult groups, respectively. The anti-HBc was detected in 2 out of 38 children and 10 out of 61 adults, but none of them became chronic hepatitis B carriers or developed clinical disease. It is recommended that everyone with anti-HBs values below 100 mlU/ml two months after the last dose of vaccine should be revaccinated with a booster dose within 6 months. Those with anti-HBs levels higher than 100 mlU/ml, should be checked up at 3 years; if the anti-HBs is less than 10 mlU/ml, they should be revaccinated.     

Lower long-term efficiency of intradermal hepatitis B vaccine compared to the intramuscular route in hemodialysis patients

Intramuscular (i.m.) and Intradermal (i.d.) vaccination against hepatitis B (HB) are efficient in hemodialysis patients. We retrospectively analysed the response of 32 patients during 48 consecutive months and compared the results of the two vaccination routes using the recombinant vaccine (Engerix, SKB). Thirteen patients were vaccinated with 5 mcg i.d. every 2 weeks (total 8 doses), plus an i.m. dose on month (M) 12 (group A). Nineteen patients (group B) were vaccinated with 4 i.m. doses of 20 mcg each, on months M0, 1, 2 and 12. HB antibodies were measured on M5, M11, M13, M24, M36 and M48. An additional 20 mcg i.m. dose was given with titers below 10 mIU/ml. Seroconversion, seroprotection and antibody levels were equivalent in both groups up to M13; with the exception of seroconversion rates, a significantly different response was observed afterwards (A/B, in mIU/ml): M5: 399 +/- 107 vs 342 +/- 69, M13: 536 +/- 118 vs 673 +/- 61, M24: 278 +/- 94 vs 595 +/- 81, P=0.02, and M48: 68 +/- 29 vs 565 +/- 92, P=0.003. Early HB(S)AB levels did not correlate with those found four years later in both groups. An additional booster dose was given 8 times in 4 group A patients (1-3 doses/patient) and 3 times in 1 group B patient. Immune response to HB vaccine in hemodialysis patients is initially equivalent by both immunization routes. Late antibody titers were found significantly lower in i.d. immunization with more frequent booster doses needed.     

Vaccination against hepatitis B virus at the Lyon Pasteur Institute. A seven-year evaluation]

Results of immunization against hepatitis B among Pasteur Institute staff members are reported. Prior to immunization, 439 subjects were tested for hepatitis B virus (HBV) markers, including HBs antigen, anti-HBs antibody, and anti-HBc antibody (Ausria, Ausab, Corab assays; Abbott). Forty-seven subjects tested positive for anti-HBs antibody. 317 subjects negative for all the HBs markers studied were given three intramuscular doses of Hevac B (Pasteur vaccins) at one-month intervals. Anti-HBs antibodies were assayed after the third injection with the following results: mean titer, 1,454 mIU/ml, standard deviation, 5,349 mIU/ml, and range, 4 to 41,100 mIU/ml. Anti-HBs titers above 10 mIU/ml were found in 879.4% of subjects. Non-responders and weak responders (anti-HBs titer under 10 mIU/ml) were given a fourth dose of vaccine. Ultimately, after the last (third of fourth) injection 97.6% of subjects had protective antibody titers. No case of HBV infection was seen during the seven-year follow-up period.     

A prospective study of in vitro anti-HBs producing B cells (spot-ELISA) following primary and supplementary vaccination with a recombinant hepatitis B vaccine in insulin dependent diabetic patients and matched controls.

A prospective study of the immune response after hepatitis B vaccination was carried out in 32 insulin dependent diabetes mellitus (IDDM) patients and their age and sex matched healthy controls. A sensitive, immunoenzymatic technique was used, able to detect in vitro specific antibody production by mitogen stimulated individual B cells. In-vivo serologic response after vaccination with a standard scheme (0, 1 and 6 months) of 20 micrograms recombinant hepatitis B (HB) vaccine was significantly impaired in the IDDM patients both with respect to the number of nonresponders (25 versus 3%, P less than 0.05) and antibody titers reached (1,377 vs. 9,060 IU/L, P less than 0.05). The total number of in vitro IgM- and IgG-class immunoglobulin producing B cells as detected by the spot-ELISA, was found to be comparable in both groups. Specific IgG anti-HBs (and to a lesser extent IgM anti-HBs) showed impairment in the diabetic population as a whole. The number of IgG anti-HBs producing B cells was markedly depressed one month following vaccination, which is probably a reflection of homing of B cells outside the circulation. Responding subjects were identified early during their vaccination by the detection of in vitro anti-HBs production using the spot-ELISA. Non-responding healthy subjects and IDDM patients as a group showed a low number of IgG anti-HBs spots, suggesting a reduced specific memory B cell frequency. In 13 of 15 hypo- and nonresponders with positive IgG anti-HBs spots supplementary vaccination(s) resulted in improved anti-HBs levels.     

Antibody persistence and immune memory in healthy adults following vaccination with a two-dose inactivated hepatitis A vaccine: long-term follow-up at 15 years

Long‐term persistence of vaccine‐induced immune response in adults was assessed annually for 15 years following primary immunization with a two‐dose inactivated hepatitis A vaccine. In 1992, 119 and 194 subjects aged 17–40 years and naïve for hepatitis A virus (HAV) were enrolled in two studies to receive 1,440 ELISA units (El.U) of inactivated hepatitis A vaccine (Havrix?, GlaxoSmithKline Biologicals, Belgium) according to a standard 0, 6 or an extended 0, 12 months schedule, respectively. Serum samples were taken 1 month after the second vaccine dose and every consecutive year up to 15 years after primary vaccination for measurement of anti‐HAV antibody concentrations (NCT00291876 and NCT00289757). At year 15, 100% (48/48) and 97.3% (108/111) of subjects vaccinated at 0, 6 or 0, 12 months remained seropositive for anti‐HAV antibodies, with geometric mean concentrations (GMCs) of 289.2 and 367.4 mIU/ml, respectively. An additional dose of HAV vaccine (1,440 El.U) was administered to the six subjects who had become seronegative for anti‐HAV antibodies since year 11. All subjects mounted a humoral immune response to the additional HAV challenge dose, although post‐challenge anti‐HAV antibody levels remained low in one subject. These studies represent the longest annual follow‐up of hepatitis A vaccine in healthy adults. The immune response induced by two doses of this inactivated HAV vaccine was shown to persist for at least 15 years. No difference in long‐term antibody persistence was observed between the two primary vaccination schedules, reinforcing the potential for flexibility in the timing of the second primary vaccine dose. J. Med. Virol. 83:1885–1891, 2011. © 2011 Wiley‐Liss, Inc.     

Predicted 30‐year protection after vaccination with an aluminum‐free virosomal hepatitis A vaccine

Few studies have examined the duration of protection following vaccination against hepatitis A virus (HAV) with currently licensed HAV vaccines. This study explored the long‐term immunogenicity in individuals vaccinated with the virosomal hepatitis A virus, Epaxal®. Adult volunteers (N = 130) previously enrolled into four different studies between 1992 and 1994 and who had completed a 0/12‐month immunization regimen (primary and booster dose) were asked to participate in this follow‐up study. Yearly anti‐HAV titers up to 6 years following booster vaccination, and then once 9–11 years after booster were measured using two assays, Enzygnost® and AxSYM® HAVAB 2.0. Based on the Enzygnost® assay, the seroprotection rate 9–11 years after booster was 100%, with a geometric mean concentration (GMC) of anti‐HAV antibodies of 526 mIU/ml. Females had markedly higher GMCs than males (741 mIU/ml vs. 332 mIU/ml). Using an anti‐HAV cut‐off titer of ≥10 mIU/ml, a linear mixed mathematical model predicted a median duration of protection of 52.1 years. A duration of protection ≥35.7 years was predicted for 95% of subjects. A more stringent cut‐off of ≥20 mIU/ml shortened the median predicted duration of protection to 45.0 years. In conclusion, a two‐dose Epaxal® vaccination regimen confers in healthy adults a real‐time protection of at least 9–11 years; this protection is predicted to last at least 30 years in over 95% of individuals. Further studies are necessary to assess the real duration of seroprotection and whether an additional booster is necessary later. J. Med. Virol. 82:1629–1634, 2010. 2010 Wiley‐Liss, Inc.