Comparative immunogenicity and safety of two dosing schedules of a combined hepatitis A and B vaccine in healthy adolescent volunteers: an open, randomised study

An open, randomised study was undertaken to demonstrate the equivalence in immunogenicity and to determine the reactogenicity and safety of two dosing schedules (0, 6 or 0, 12 month) of an adult formulation of a combined hepatitis A and B vaccine containing 720 EL.U. of inactivated hepatitis A antigen and 20 μg of hepatitis B surface antigen (Twinrix™, SmithKline Beecham Biologicals, Belgium) in 240 healthy volunteers aged 12–15 years. The vaccine was well tolerated when administered using either vaccination schedule. At month 7, 98.1% of subjects completing the 0, 6 month vaccination schedule were seroprotected against hepatitis B (anti-hepatitis B surface antigen (anti-HBs)10 mIU/ml) and 100% were seropositive for anti-hepatitis A virus (anti-HAV) antibodies (i.e., 33 mIU/ml). The corresponding geometric mean titres (GMTs) were 2791 mIU/ml for anti-HBs and 5992 mIU/ml for anti-HAV antibodies. At month 13, 97% of subjects assigned to the 0, 12 month vaccination schedule were protected against hepatitis B and 99% were seropositive for anti-HAV antibodies. The corresponding GMTs were 4340 and 8472 mIU/ml, respectively. A combined response (i.e., subjects, who were seropositive for anti-HAV antibodies and seroprotected for anti-HBs antibodies) was achieved in 98% of subjects vaccinated according to the 0, 6 month interval and in 96% of subjects vaccinated using the 0, 12 month schedule. The reactogenicity of both vaccination schedules was also equivalent. The results thus show that the combined hepatitis A and B vaccine can be administered using flexible vaccination intervals, which make it suitable for use in large-scale hepatitis immunisation programmes.     

Antibody persistence six years after two doses of combined hepatitis A and B vaccine

Persistent immunity to hepatitis A and hepatitis B antibodies six years after vaccination of adolescents (aged 12–15 years) with a combined hepatitis A and B (HAB) vaccine following a 0, 6 month or a 0, 12 month schedule was assessed. Yearly (Year-2–6) serum samples were tested for anti-HAV and anti-HBs using EIA. Subjects with anti-HBs concentrations <10 mIU/mL (14/23) at Year-5 or Year-6, received an additional HBV vaccine dose ∼12 months after Year-6. Blood samples were collected pre-booster and 1 month post-booster to assess booster response. 240 subjects were vaccinated in the study; at Year-6, data were available from 88 subjects. At that time 84.8% (39/46; 0, 6 month) and 92.9% (39/42; 0, 12 month) of subjects had anti-HBs concentrations ≥10 mIU/mL. All but one of the 14 boosted subjects responded to the additional HBV vaccine dose with anti-HBs concentrations ≥100 mIU/mL. All seroconverted subjects who returned at Year-6 were seropositive for anti-HAV. Simplification, reduced number of doses and similar long-term persistence of immunity make the 0, 6 month and 0, 12 month schedule preferable for immunization against HAV/HBV in this population.     

The first combined vaccine against hepatitis A and B: an overview

Hepatitis A and B infections are prevalent world-wide and are a significant cause of morbidity and mortality. A vaccine providing dual protection against hepatitis A and B is now available (Twinrix, SmithKline Beecham Biologicals). Six pivotal vaccine trials, involving 843 healthy adults, aged between 17 and 60 years and vaccinated following a 0, 1, 6 month schedule are discussed. At month 2 more than 99% of the vaccinees were seropositive for anti-HAV and 84% were protected against hepatitis B. The third dose induced a 12-fold increase in geometric mean titres (GMTs) to 5404 mIU/ml. One month after completion of the vaccination course nearly all vaccinees had protective titres against hepatitis B with a GMT of 4818 mIU/ml. Long term follow-up data until month 48 is available for two studies. At month 48 all 129 vaccinees sampled were still positive for anti-HAV antibodies and > 95% were still protected against hepatitis B. The combined hepatitis A and B vaccine Twinrix proves to be consistently safe, well tolerated and highly immunogenic and compares well with serological responses reached with monovalent vaccines. This combined hepatitis A and B vaccine offers more convenience, potentially better compliance and lower administration costs.     

倍尔来福TM甲、乙型肝炎联合疫苗安全性和免疫原性研究

目的 观察倍尔来福~(TM)甲、乙型肝炎(甲、乙肝)联合疫苗的安全性和免疫原性。方法以高中一年级(成人组)和小学1～5年级(儿童组)学生为研究对象,按对甲、乙肝病毒均易感、只对甲肝病毒易感和只对乙肝病毒易感分为AB组、A组和B组,按0、1和6个月三剂程序分别接种甲、乙肝联合疫苗、灭活甲肝疫苗和重组乙肝疫苗。疫苗剂量成人组每剂含甲肝病毒抗原500U和(或)HBsAg10μg,儿童组减半。疫苗接种后72h内观察副反应,免疫后2、7个月采集血清标本检测抗-HAV和抗-HBs。结果 儿童AB组和成人AB组局部副反应发生率分别为0.58％(2/344)和2.56％(8/312),全身副反应发生率分别为9.88％(34/344)和5.45％(17/212),与对照组相比差异无显著性。局部反应主要是轻度疼痛,全身反应主要是低热。免疫后7个月,两组抗-HAV阳转率均为100％,与A组相同;抗体滴度(GMT)分别为33 910mIU/ml和23 435 mIU/ml,显著高于A组;两组抗-HBs阳转率分别为97.30％和96.63％;GMT为103 mIU/ml和102 mIU/ml,抗-HBs阳转率及GMT均与B组差异无显著性。结论 倍尔来福~(TM)甲、乙肝联合疫苗与单价甲肝灭活疫苗和单价重组乙肝疫苗具有相同的安全性和免疫原性。     

Antibody persistence and immune memory elicited by combined hepatitis A and B vaccination in older adults

Response to hepatitis A and B vaccines has been reported to decline with age. This open, prospective, single-site study examined the long-term response to the combined hepatitis A/B vaccine Twinrix in 98 primary responders aged 45-67 years. Levels of antibody against hepatitis A virus (HAV) and hepatitis B surface antigen (HBs) were tested 30 months after initial vaccination. At this stage, all participants remained seropositive for anti-HAV and 70% for anti-HBs. A booster vaccination was offered to those who had responded to the first vaccination but then lost protective levels of anti-HBs. An anamnestic response was observed in all cases.     

Long-term persistence of anti-HBs after vaccination with a recombinant DNA yeast-derived hepatitis B vaccine: 8-year results

The aim of this study was to evaluate the persistence of antibodies 7 years after hepatitis B booster administration in healthy adult volunteers who were vaccinated in 1987. In October 1986, 188 seronegative, healthy adult volunteers (117 men and 71 women) were vaccinated with a 20 μg dose recombinant DNA yeast-derived hepatitis B vaccine. Mean age of the study group was 23.3 years (±0.28). Immunisation was carried out according to a 0-1-2 month vaccination schedule, with a boosterdose at 12 months. Of the 159 subjects who received the full vaccination course, 63 (40%) had a blood sample taken 8 years after the first vaccination. Of these 63 subjects, five were excluded from teh analysis due to an irregular vaccination schedule and four subjects did not complete the accompanying questionnaire on possible booster administration. So, 54 subjects remained available for further analysis. Fourteen individuals had received an additional booster of hepatitis B vaccine sometime between 1989 and 1994. The geometric mean titre (GMT) at month 13 for these 14 individuals was 1494 mIU ml⁻¹, compared with 3103 mIU ml⁻¹ for those who did not receive an interim booster. Forty subjects, who received no additional booster dose besides that of month 12, met the inclusion criteria of the follow-up study. Of these, all subjects except one were seropositive for anti-HBs at month 96 (GMT: 215.9 mIU ml⁻¹). All subjects were still anti-HBc negative at that time. Distribution of individual antibody titres revealed that overall 92.5% of subjects retained protective antibody levels (10 mIU ml⁻¹); 72.5% of vaccinees retained high levels of anti-HBs (100 mIU ml⁻¹) as compared to 99.2 and 97.0% at month 13, respectively. A positive correlation was found between the subjects' titres at month 13 and month 96. A 0-1-2 dose vaccination course with a booster dose administered at month 12, induces a protective immune response which lasts at least until 7 years after the full vaccination course of the subjects. A positive correlation was found between the anti-HBs antibody titres at month 13 and month 96.     

Immunity to hepatitis A and B persists for at least 15 years after immunisation of adolescents with a combined hepatitis A and B vaccine

BackgroundThe exact duration of antibody persistence to hepatitis A and B and the need for booster dosing following primary immunisation remains undefined. A long-term study was designed to follow antibody persistence and immune memory on an annual basis for up to 15 years following vaccination during adolescence.MethodsSubjects received a combined hepatitis A and B vaccine (Twinrix™, GSK Vaccines, Belgium) at 12–15 years of age, either as 2-dose of the adult formulation or 3-dose of the paediatric formulation. Blood samples were taken every year thereafter to assess antibody persistence and immune memory to hepatitis A and B. Antibodies to hepatitis A virus (anti-HAV) and hepatitis B surface antigen (anti-HBs) were measured at Years 11–15. At Year 15 immune memory was further assessed by measuring the anamnestic response to a challenge dose of the monovalent vaccine, which was administered to subjects whose antibody concentrations fell below the pre-defined cut-offs (anti-HAV: <15 mIU/mL; anti-HBs: <10 mIU/mL).Results209 subjects returned for follow-up at Year 15 of whom 162 were included in the long-term according-to-protocol immunogenicity cohort. All subjects remained seropositive for anti-HAV antibodies, while 81.1% and 81.8% still had anti-HBs antibodies ≥10 mIU/mL in the 2- and 3-dose groups, respectively. Following hepatitis B vaccine challenge dose administration to 19 subjects, all except one in the 3-dose group, mounted a robust anamnestic response. The safety and reactogenicity profile of the hepatitis B challenge was consistent with previous experience.ConclusionImmunity to hepatitis A and B persists 15 years after adolescent vaccination with a combined hepatitis A and B vaccine. Highly effective anamnestic response indicates that a booster dose should not be required for 15 years after primary vaccination.Trial registrationhttp://www.clinicaltrials.gov NCT00875485.     

Immunogenicity and reactogenicity of the combined hepatitis A and B vaccine in young adults

The combination of hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccinations can offer convenience, increased compliance and cost saving. We have studied the immunogenicity, reactogenicity and safety of combined hepatitis A and B vaccination in young adults (16-35 years old). Eighty healthy young adults were divided into two random groups. One group received the combined hepatitis A and B vaccine (HAB) in one arm while the other group was administered concomitant hepatitis A and B vaccines (HAV + HBV) in the right and left arms, respectively. The immunogenicity, reactogenicity and safety were assessed after each dose in both the groups. In local symptoms, the percentage of the combined HAB group was lower than the HAV + HBV group, and the general symptoms were noted in approximately 30% of each group without any significant difference. No serious adverse effects were noted. All the subjects were seropositive for antibody to hepatitis A virus (anti-HAV) after one dose of vaccine, and remained seropositive after three doses in both groups. The seropositive rate for antibody to hepatitis B surface antigen (anti-HBs) was significantly higher (84%) in the combined HAB group than the concomitant HAV + HBV group (62%), (p<0.05) after dose two, and all the subjects were seropositive (100%) after the third dose. The GMTs of anti-HAV and anti-HBs were not significantly different between groups 1 and 2 (p>0.1) except in month 6 when the GMT of anti-HBs was higher in HAB group (p=0.0039). The combined HAB vaccine was found to be safe, well tolerated and had less local symptoms in young adults. The immunogenicity and reactogenicity were similar to the concomitant HAV + HBV vaccines.     

Long-term antibody persistence in children primed and boosted with a DTPw-HBV vaccine at 2, 4, 6, 18, months of age

This paper presents 7- and 10-year follow-up immunogenicity data from two studies, which explored long-term persistence induced by combined tetravalent DTPw-HBV vaccines. The 10-year follow-up study compared two identical antigen-content, but different formulations of DTPw-HBV vaccine (adsorbed on either Al(OH)(3) or Al(PO(4)), whilst the 7-year follow-up study compared two different formulations of DTPw-HBV vaccines containing 5 and 10 microg of hepatitis B surface antigen (HBsAg), following a birth dose of HBV. Primary vaccination took place at 2, 4, 6 months and booster dosing at 18 months. A booster dose of local DTPw vaccine was given at 4 years of age to all returning subjects. At the end of the 7-year study, 90.9% subjects receiving 10 microg HBsAg had anti-HBs antibody concentrations > or =10mIU/ml; the majority of subjects remained seroprotected against diphtheria and tetanus (> or =90.9 and 100%, respectively) and 100% had seropositive levels for pertussis antigens. At the end of the 10-year follow-up study, > or =60.9% subjects had seroprotective concentrations of anti-HBs antibodies; > or =95.2 and 100% subjects were seroprotected against diphtheria and tetanus, respectively; > or =78.3% subjects were seropositive for pertussis. The results demonstrate long-term antibody persistence induced by combined DTPw-HBV vaccine.     

DTPw-HB and Hib primary and booster vaccination: combined versus separate administration to Latin American children

This multicentre study was designed to establish the reactogenicity and immunogenicity profiles of primary and booster vaccination with diphtheria, tetanus, and pertussis whole-cell-hepatitis B/Haemophilus influenzae type-b (DTPw-HB/Hib) administered as either a syringe mix or as separate injections in 400 Latin American children. Both vaccine regimens were equally well tolerated and elicited post-primary excellent seropositivity rates at or close to 100% for all five component antigens. With regard to HB, 100% of subjects in the combined vaccination group, and 98.8% subjects in the separate injection vaccination group reached seroprotective antibody concentrations (>or=10 mIU/ml) 1 month after the primary vaccination course. Equally high anti-PRP antibody concentrations were reached 1 month after vaccination, with 100% of seroprotected subjects in the combined vaccination group (antibody concentrations >or=0.15 microg/ml), against 99.4% in the separate injection vaccination group. Seroprotective anti-HBs and anti-PRP antibody concentration levels persisted approximately 1 year after the primary vaccination course, just prior to booster vaccination. Finally, a significant increase of all antibody concentrations could be observed after the booster vaccination, since all but one subject in the separate injection vaccination group had protective levels of anti-HBs and anti-PRP antibodies 1 month after the booster dose. These results suggest that the combination of DTPw-HB and Hib vaccines provides an effective means for increasing vaccine coverage in childhood vaccination programmes.     

孩尔来福甲型肝炎灭活疫苗0,12个月免疫程序研究

目的　对孩尔来福 (HealiveR○)甲型肝炎 (甲肝 )灭活疫苗的安全性、免疫原性及适宜儿童的剂量进行研究。方法　在某山区两个农村筛选 4～ 10岁甲肝病毒抗体 (抗 HAV)阴性的 85名易感儿童。以自然村随机分为两组 ,按 0 ,12个月免疫程序分别接种北京科兴生物制品有限公司生产的每剂 2 50U 0 .5ml和 50 0U 1ml甲肝灭活疫苗 ,观察免疫后局部反应和全身反应 ,检测初次免疫 (初免 )后 2 1天、12个月及全程免疫后 1个月抗 HAV阳转率和抗体几何平均滴度 (GMT )。结果　两组均未见严重局部反应和全身反应 ;2 50U 0 .5ml组和 50 0U 1ml组初免后 2 1天 ,抗 HAV阳转率分别为94.4%和 10 0 .0 % ,GMT分别为 195mIU ml和 3 70mIU ml ;初免后 12个月抗 HAV全部阳转 ,GMT分别达 3 61mIU ml和 456mIU ml(P >0 .0 5) ;全程免疫后 1个月 ,GMT分别达 14 893mIU ml和2 1696mIU ml。结论　孩尔来福甲肝灭活疫苗的安全性和免疫原性好 ;每剂 2 50U 0 .5ml适宜儿童 ;0 ,12个月免疫程序更适宜中国儿童     

不同剂量国产重组酵母乙型肝炎疫苗成年人免疫效果及影响因素研究

目的 通过随机双盲对照试验,评价10μg和20μg国产重组酵母(CHO)乙型肝炎(乙肝)疫苗应用于成年人的免疫效果,以及影响免疫效果的个体因素.方法 在北京市4个区县范围内选择18～45岁未接种乙肝疫苗、乙肝五项指标均为阴性的642名成年人作为研究对象,随机分为两组,按照"0-1-6"程序分别接种10μg和20μg CHO乙肝疫苗,通过问卷方法调查每个对象可能影响乙肝疫苗免疫效果的个体因素.于接种第三针1个月后采血,以雅培化学发光的方法检测抗-HBs滴度值,抗-HBs阴性者采用荧光定量PCR方法进一步检测HBV DNA,利用logistic回归分析方法分析影响抗-HBs阳转的个体因素.结果 10μg和20μg两个剂量组抗-HBs阳转率分别为88.8%(95%CI:85.4%～92.2%)和95.3%(95%CI:93.0%～97.6%).按照抗-HBs＜100 mIU/ml为低无应答标准,低无应答率分别为34.3%和17.4%;抗体几何平均滴度(GMT)分别为173.42 mIU/ml和588.51 mIU/ml.多因素分析表明:患糖尿病、配偶为乙肝病毒感染者以及大年龄组人群是抗体阳转不利因素,而20μg疫苗剂量有利于抗体阳转.结论 CHO乙肝疫苗20μg免疫效果优于10μg,乙肝疫苗免疫效果评价应考虑多因素的影响.     

Comparison of the reactogenicity and immunogenicity of a two injection combined high-dose hepatitis A and hepatitis B vaccine to those of Twinrix

Twinrix (SmithKline Beecham Biologicals) is a combined hepatitis A and B vaccine licensed with a three-dose schedule. A two-dose combined hepatitis A and B vaccine would facilitate immunisation programs. In this prospective study, 100 healthy adults, aged between 18 and 40, were enrolled. A first group of 50 was given a high-dose vaccine at month 0 and 6. A second group of 50 received Twinrix at month 0, 1 and 6.The reactogenicity was assessed after each vaccine dose. There were no severe local adverse events. Seven severe systemic reactions occurred, of which five were fatigue, one was headache and one consist in gastrointestinal symptoms. They all resolved during the 4-day follow-up period. One serious general adverse event was reported, but was clearly unrelated to the vaccine. Thus, both vaccines were well tolerated.The immunogenicity was evaluated by testing for anti-HBs and anti-HAV antibodies. Seroconversion rates and geometric mean titres (GMTs) were compared. At month 7, the anti-HAV GMTs were higher in the high-dose group than in the Twinrix group and, inversely, the anti-HBs GMTs were slightly higher in the Twinrix group than in the high-dose group. At month 7, all subjects in both groups were positive for anti-HAV. All subjects in the high-dose group and 97.6% subjects in the Twinrix group had seroconverted for anti-HBs. Therefore, it can be concluded that with two injections of the high-dose hepatitis A and B vaccine, 6 months apart, a similar immune response can be obtained as induced with three doses of Twinrix at months 0, 1 and 6.     

Safety and immunogenicity of hepatitis A vaccine in infants: a candidate for inclusion in the childhood vaccination programme

Forty-eight infants received a single dose (720 ELISA units = 0.5 ml) of inactivated hepatitis A vaccine at the fifth month of age with booster at the 11th month of age, together with the second and third doses of the vaccines compulsory under Italian law (diphtheria, tetanus, oral polio and hepatitis B). Overall, the seroconversion rate was 100%. The anti-HAV geometric mean titre (GMT) reached 3,021 mIU/ml in infants born to anti-HAV-negative mothers, but only 399 mIU/ml in infants born to anti-HAV-positive mothers. Hepatitis A vaccine was immunogenic, safe and well tolerated without significant side-effects. There seems to be no reason for not including it in childhood vaccination programmes particularly in low endemic HAV areas.     

Long-term (5-year) antibody persistence following two- and three-dose regimens of a combined hepatitis A and B vaccine in children aged 1–11 years

This study compared the long-term persistence of anti-hepatitis A (anti-HAV) and B (anti-HBs) antibodies, 5 years after vaccination of subjects aged 1–11 years with a combined hepatitis A and B vaccine either in a two-dose (0, 6 months, Adult formulation) or a three-dose (0, 1, 6 months, Paediatric formulation) schedule. At the end of the 5 years, all subjects (100%) in both groups continued to have anti-HAV antibodies ≥15 mIU/mL, while 94–97% of subjects in both groups had anti-HBs antibody concentrations ≥10 mIU/mL. Subjects with anti-HBs antibody concentration ≤10 mIU/mL were administered a challenge dose of hepatitis B vaccine. All subjects mounted a vigorous immune response to the challenge indicating the presence of immunological memory to HBV.     

Long-term immunogenicity of hepatitis B vaccination in a cohort of Italian healthy adolescents

In 1992, 620 adolescents were vaccinated against hepatitis B. Anti-HBs concentrations were measured in 480 (77.4%) adolescents 1 month after completion of the primary course of vaccination. To assess the persistence of anti-HBs, 347 and 228 of such vaccinees were retested for anti-HBs in 1999 and for anti-HBs and anti-HBc in 2003. More than 10 years after vaccination, individuals with anti-HBs >or=10 mIU/ml were considered protected while those with antibody <10 mIU/ml were given a booster dose and retested 2 weeks later. Check performed in 2003 showed that 208/228 (91.2%) vaccinees retained protective concentrations of anti-HBs. All vaccinees were anti-HBc negative. 11 of the 12 (91.7%) individuals who were given a booster dose of vaccine showed a vigorous anamnestic response while the remaining one showed a weak response (10.6 mIU/ml). These data suggests that hepatitis B vaccination can confer long-term immunity and that immunological memory can outlast the loss of antibody. Hence, the use of routine booster doses of vaccine does not appear necessary to maintain long-term protection in successfully vaccinated immunocompetent individuals.     

Long-term persistence of anti-HBs after vaccination against HBV: an 18 year experience in health care workers

The aim of the present study was to evaluate the long-term persistence of seroprotection after hepatitis B virus (HBV) vaccination. A total of 422 health care workers (HCWs) were evaluated 4.8-18.8 years after primary immunization (mean follow-up 11.8 years); 241 of them had received plasma-derived vaccines and 181 had been given yeast-derived vaccines; 107 subjects received a booster dose of yeast-derived vaccine 6 years after primary immunization with either plasma-derived or yeast-derived vaccines. Seroprotection was assumed when the anti-HBs titers were >10 mIU/ml. The overall response after primary immunization was 98.8%. Among subjects who reached a 10 year follow-up, those treated with plasma-derived vaccine had a seroprotection rate of 87.8 compared to 81.6% of those vaccinated with yeast-derived vaccines (P<0.001). Anti-HBs geometric mean titers (GMTs) after primary immunization were similar in the two groups, but were significantly lower at 10 years follow-up in the group that had received a yeast-derived vaccine (104 mIU/ml versus 244 mIU/ml in those who used a plasma-derived vaccine, P<0.05). Anti-HBs GMTs in the 107 subjects given the booster dose were 242 mIU/ml pre-booster titer, and rose to 35,171 mIU/ml after the booster dose. A mean 10.1 years after the booster dose, GMTs were 952 mIU/ml. Overall, the anti-HBs seroprotection rate was 95.4% (102 subjects). Based on GMT results, no booster dose is necessary in healthy adults for at least 10 years after primary immunization.     

Immunogenicity of two paediatric doses of monovalent hepatitis B or combined hepatitis A and B vaccine in 8-10-year-old children

Hepatitis A and B vaccines are highly immunogenic in three-dose schedules. To obtain an equivalent result in children with two paediatric doses would be of significant benefit. The purpose of this study was to measure the immunogenicity of a two-dose schedule in children with two licensed recombinant HBsAg containing vaccines given at paediatric doses, one of them combined with hepatitis A. Seven-hundred and four healthy school children aged 8-10 years were recruited in an open label study to receive either Twinrix Pediatric (360 El.U HAV antigen; 10 microg HBsAg) or Recombivax (2.5 microg HBsAg) vaccine intramuscularly 6 months apart. The seroconversion (>/=1 mIU/ml for anti-HBs antibodies and >/=33 mIU/ml for anti-HAV antibodies), seroprotection (anti-HBs >/=10 mIU/ml) rates and the geometric mean titers (GMTs) were determined 4-8 weeks after the second dose. The anti-HBs seroconversion rate was 97.1% with Twinrix and 97.2% with Recombivax. The seroprotection rates were 96.5 and 94.4%, respectively (P = 0.17). The GMT was higher with Twinrix than with Recombivax (3248 mIU/ml versus 742 mIU/ml, P < 0.0001). All the children vaccinated with Twinrix seroconverted to HAV and the GMT was 5168 mIU/ml. The obtained results suggest that two paediatric doses of hepatitis vaccines are highly immunogenic in 8-10-year-old children. This schedule could facilitate a greater vaccine acceptance and the addition of hepatitis A vaccine to existing adolescent universal hepatitis B virus immunization programs.     

广西壮族自治区隆安县乙型肝炎疫苗全程接种后的免疫记忆研究

目的了解接种全程乙型肝炎（乙肝）疫苗后的免疫记忆情况。方法1987-1989年出生时接种乙肝血源疫苗的1201名新生儿,以及1996-1999年出生时接种乙肝酵母重组疫苗的2484名新生儿,于2005年随访时检测乙肝表面抗原（HBsAg）、表面抗体（抗-HBs）和核心抗体（抗- HBc）,结果959名3项乙肝病毒（HBV）标志物均阴性,其中228名接种乙肝血源疫苗,731名接种乙肝酵母重组疫苗,于加强免疫1针乙肝酵母重组疫苗后15 d时检测其抗-HBs。此外,随机选择11名加强免疫后无应答和22名有应答者,应用酶免疫斑点法（ELISPOT）测定白细胞介素-2（IL-2）。有初次免疫后抗-HBs定量检测资料者190名,比较其初次免疫和加强免疫后抗-HBs水平。结果加强免疫后,79．82%接种乙肝血源疫苗者抗-HBs阳转,几何平均滴度（GMT）为325．69 mIU/ml;95．62%接种乙肝酵母重组疫苗者抗-HBs阳转,GMT为745．18 mIU/ml。加强免疫后所产生的抗-HBs水平与初次免疫后抗体滴度有关。加强免疫后抗-HBs阳转者的IL-2阳性率（40．91%）也高于无应答者（P＜0．01）。结论在乙肝疫苗初次免疫后,抗-HBs转阴者中,大部分仍具有免疫记忆,仅少部分在长期随访中丧失免疫记忆。因此,在高流行地区,对丧失免疫记忆者应进行乙肝疫苗加强免疫。     

Immunogenicity and safety of an investigational AS02(v)-adjuvanted hepatitis B vaccine in patients with renal insufficiency who failed to respond or to maintain antibody levels after prior vaccination: results of two open, randomized, comparative trials

An investigational AS02_v-adjuvanted hepatitis B (HB-AS02) was compared with a licensed conventional recombinant hepatitis B vaccine (HBVAXPRO™; Sanofi Pasteur MSD, Lyon, France) in pre-dialysis, peritoneal dialysis and hemodialysis patients aged ≥18 years who had failed either to respond to prior vaccination with a conventional hepatitis B vaccine (Study A; n = 251) or to maintain protective antibody concentrations after prior hepatitis B vaccination (Study B; n = 181). These were open, randomized, comparative trials. Mean (range) age was 65.9 (31-92) and 64.6 (29-92) years in the two studies, respectively. In Study A, two doses of HB-AS02 given one month apart were found to be superior to two doses of the licensed vaccine in terms of seroprotection rate (76.9% versus 37.6%) and anti-HBs geometric mean antibody concentration (GMC; 139.3 versus 6.9 mIU/ml), with antibody concentrations ≥100 mIU/ml in 61.1% and 15.4% of subjects in the two groups, respectively. In Study B, one month after administration of a single booster dose, seroprotection rates were 89.0% in the HB-AS02 group and 90.8% in the licensed vaccine group, 81.3% and 60.9% of subjects had antibody concentrations ≥100 mIU/ml, and anti-HBs GMCs were 1726.8 and 189.5 mIU/ml. HB-AS02 was found to be more reactogenic than the licensed vaccine. In summary, the investigational HB-AS02 vaccine induced higher seroprotection rates and anti-HBs GMCs than a licensed conventional hepatitis B vaccine in uremic patients who had failed to respond or to maintain protective antibody titers after prior hepatitis B vaccination.