中国甲型肝炎减毒活疫苗和灭活疫苗免疫效果与安全性评价

目的评价中国甲型肝炎(甲肝)减毒活疫苗(HepA-L )和甲肝灭活疫苗(HepA-I )的安全性及免疫效果,为甲肝暴发疫情疫苗应急接种提供参考依据。方法用美国雅培(Abbott)公司生产的抗甲肝病毒抗体(抗一HAV)试剂筛查未感染HAV的6~9岁儿童。将人选对象随机分为4组,分别接种国产HepA-L和HepA-I,以国产重组乙肝疫苗(酿酒酵母)( HepB-SCY)为阴性对照,G1axoSmithKline Biologicals S.A.(GSK)生产的HepA-I为阳性对照,采取随机双盲方法观察接种疫苗后30 min及24,48,72 h的不良反应发生率。采用美国Abbott Laboratories生产的HAVAB 2.0试剂,利用微粒子酶免疫分析与电化学发光免疫测定法(MEIA)检测1,2,4周以及12个月的HAV IgG抗体水平。结果各组未发现严重不良反应,不良反应主要表现为发热、接种部位疼痛、硬结等。国产HepA-L和HepA-I组不良反应发生率分别为13.95%和15.25%,阳性对照组为16.80%,阴性对照组为25.62%,各组间差异无统计学意义。接种2周后,国产HepA-L和HepA-I抗体阳转率分别为85.00%和94.59%;接种后第4周,抗体阳转率达到100%;接种2,4.12周时试验组、阳性对照组HAV IgG抗体水平高于阴性对照组;接种12个月后,国产HepA-I组甲肝抗体水平高于阳性对照组。结论国产HepA-L和HepA-I以及进口HepA-I安全性良好,均具有较好的免疫效果。     

连续三批甲型肝炎灭活疫苗在儿童中应用的免疫原性和安全性研究

目的 考核连续三批甲肝灭活疫苗孩尔来福(R)临床应用的免疫原性和安全性及质量的稳定性、批间一致性.方法 采用随机双盲设对照的临床试验设计,试验用疫苗为连续三批次的孩尔来福(R)和进口对照疫苗.受试者为400名1～8岁抗-Hav阴性健康儿童,随机分配到四个试验组,每组100人,孩尔来福(R)剂量为每支250 U/0.5 ml,对照疫苗剂量为每支720 Elu/0.5 ml,按照0和6个月程序接种疫苗.接种后进行30 min即时反应观察以及24、48、72 h的随访观察,并在第一针免疫后1、6、7个月采血检测甲肝抗体.结果 四个试验组免后7个月抗体阳转率均为100%;三批孩尔来福(R)的GMT为3237.06～3814.14 mIU/ml,差异无统计学意义;对照疫苗GMT为1467.49 mIU/ml.接种疫苗后孩尔来福(R)和对照疫苗组不良反应发生率在1%～5%之间,以轻度和中度发热为主,未见严重不良反应发生.结论 孩尔来福(R)质量稳定,批间一致性和安全性良好.     

Long-term clinical observation of the immunogenicity of inactivated hepatitis A vaccine in children

110 children who were given the complete course of the inactivated hepatitis A vaccine (Havrix™) were followed up 10 years later. Age-matched healthy children who were not inoculated served as controls. One month after two primary injections, all children were positive for serum antibody. After 10 years, 99.09% of inoculated children remained positive for serum anti-HAV antibody, with a geometric mean concentration (GMC) of 61.59 mIU/mL. GMC values following a secondary immunization in children with antibody levels <20 mIU/mL were significantly elevated (567.9 mIU/mL), compared with the primary injection alone. Havrix™ appears to induce persistent immunity and potent immune memory.     

国产甲型肝炎灭活疫苗的安全性与免疫原性初步观察

目的 评价国产甲型肝炎灭活疫苗的安全性和免疫原性。方法 对健康易感儿童1％名和成人206名随机分为4组，107名儿童(A组)和131名成人(B组)接种国产甲肝灭活疫苗，另69名儿童(c组)和75名成人(D组)作为对照接种史克必成公司生产的甲肝灭活疫苗。国产疫苗剂量为儿童640EIU／1．0ml。成人1440EIU／1．0ml，对照疫苗剂量儿童720EIU／1．0ml，成人1440EIU／1．0ml，均采用0、6程序。观察72小时内局部和全身反应及免后1、6、7月的免疫应答水平。结果 所有接种对象均未出现明显局部和全身副反应，亦未发现免后ALT升高。初免后一个月A组和B组抗体阳性率分别为94．8％和96．7％，几何平均滴度为758．6mIU／ml和3630．8mIU／ml。全程免疫后一个月4组抗体阳性率均为100％，A组和B组抗体几何平均滴度上升至10471．2mIU／ml和12302．7mIU／m1，略高于对照的C组和D组(分别为3090．3mIU／d和3388．4mIU／ml)。结论 国产甲肝灭活疫苗具有良好安全性和免疫原性。     

Comparing live attenuated and inactivated hepatitis A vaccines: an immunogenicity study after one single dose

Introduction

While three types of hepatitis A vaccines are available in China, little data are available to compare them in terms of early antibody response. We conducted a trial to compare antibody response at 7, 14 and 28 days.

Methods

We randomized primary school children in Gansu and Jilin provinces into four groups to receive either (1) Chinese live attenuated hepatitis A vaccine (H2 strain), (2) domestic inactivated hepatitis A vaccine (Healive^®), (3) imported inactivated hepatitis A vaccine (Havrix^®) or (4) hepatitis B vaccine (Control group). We compared groups at 7, 14 and 28 days in terms of proportion of sero-conversions (≥10 mUI/ml), and Geometric Mean Concentration (GMC) of antibodies measured with a Microparticle Enzyme Immunoassay (MEIA). We compared rates of self-reported adverse events following immunization (AEFI) in the first three days.

Results

204 children received the H2 vaccine, 208 received Healive^®, 214 received Havrix^®, and 215 received hepatitis B vaccine (no differences across groups in terms of age, sex, weight and height). At seven days, sero-conversion proportions were 25%, 35%, 27% and 2% (p < 0.0001) with GMC of 6 mIU/ml, 8 mIU/ml, 6 mIU/ml and 3 mIU/ml, respectively for the four groups. At 28 days, sero-conversion proportions were 98%, 100%, 93% and 3% (p < 0.0001) with GMC of 47 mIU/ml, 71 mIU/ml, 67 mIU/ml and 3 mIU/ml, respectively. AEFI were benign and did not differ across groups (p = 0.94).

Conclusions

While our study was not able to identify differences between Havrix^®, Healive^® and H2 vaccine in terms of sero-conversion proportion and GMC between seven and 28 days, further studies should evaluate non-inferiority or equivalence of the Chinese vaccines, particularly with respect to the GMC concentration for the H2 vaccine since it could affect long-term protection.     

甲型肝炎减毒活疫苗加强免疫效果的初步研究

目的　观察甲型肝炎 (甲肝 )减毒活疫菌 (10 7.0 TCID50 )加强免疫效果 ,并同活疫苗一针法结果进行比较。方法　在河北省正定县选择 42名经事先检测甲肝抗体阴性的易感儿童 ,分别于0、2和 6个月各接种一剂甲肝减毒活疫苗 ,并于接种后 1、2、6、7、9和 12个月采集血清标本 ,观察免后抗体动态变化。结果　第 1剂接种后 1个月抗体阳转率达 81.4% ,第 2剂免后抗体阳转率达 10 0 % ,抗体水平于第 3剂免后 1个月达高峰 ,为 2 739mIU/ml,以后呈下降趋势 ,免后 12个月抗体阳转率仍为 10 0 % ,抗体水平下降至 979mIU/ml。结论　甲型肝炎减毒活疫苗加强免疫能诱导良好的免疫回忆反应 ,其免疫学效果同史克灭活疫苗相当 ,而明显高于活疫苗一针法。活疫苗加强免疫中 ,初免是基础。活疫苗加强免疫会提高疫苗保护效果 ,并延长疫苗的免疫持久性     

宝山区甲肝疫苗免疫接种成本-效益分析

[目的 ]　分析研究宝山区推行接种甲肝疫苗预防控制甲型肝炎的经济效益。 [方法 ]　参考WHO推荐的“国民收入法”评价指标。 [结果 ]　 1994～ 1998年宝山区实施接种甲肝疫苗后 ,病毒性甲型肝炎发病率明显下降 ,测算预期减少甲型肝炎病例 35 81例。计算此阶段取得的经济效益为 34 0 5 .85万元 ,扣除成本后的净效益为2 5 47.45万元。成本效益比为 1:3.97。 [结论 ]　应用WHO“国民收入法”评价指标可较好地对甲肝疫苗预防接种进行成本 -效益分析 ,结果证明其经济效益显著。     

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。     

冻干甲型肝炎减毒活疫苗的副反应和免疫原性观察

为了解国产冻干甲型肝炎(甲肝)减毒活疫苗上市后的临床安全性和免疫效果,对冻干甲肝减毒活疫苗进行了上市后的临床副反应与免疫原性研究.     

甲型肝炎灭活疫苗在大学生中加强免疫的效果研究

目的 评价甲型肝炎（甲肝）灭活疫苗在成年人中加强免疫的效果和安全性。方法 选择参加健康成年人甲肝灭活疫苗和冻干甲肝减毒活疫苗随机双盲临床试验,基础免疫前甲肝抗体阴性并完成1针甲肝灭活疫苗或减毒活疫苗的大学生作为研究对象,加强免疫1针甲肝灭活疫苗,免疫前、免疫后28 d采血,检测抗甲肝病毒抗体滴度≥20 mIU/ml为阳性。结果 加强免疫前甲肝灭活疫苗组和减毒活疫苗组GMC分别为70.80 mIU/ml、50.12 mIU/ml;阳性率分别为94.7%、65.0%。加强免疫1针甲肝灭活疫苗后,两组的抗体阳性率均为100.0%,灭活疫苗组和减毒活疫苗组GMC分别为2 816.09 mIU/ml、2 654.55 mIU/ml。结论 接种1针甲肝灭活疫苗或减毒活疫苗3年后,甲肝抗体GMC和阳性率均有不同程度降低,灭活疫苗优于减毒活疫苗,两组进行1针灭活疫苗的加强免疫效果明显。     

Population seroprotection against hepatitis a virus in Israel 18 years after introduction of inactivated vaccine into the routine childhood vaccination schedule

Vaccine against Hepatitis A virus (HAV) is part of the routine vaccination schedule in Israel since 1999. As of 2016, new recruits to the Israel Defense Forces should have been vaccinated in their childhood. This sero-survey aimed to determine immunity against HAV 18 years after childhood vaccination, and to re-evaluate the need for HAV vaccination booster upon recruitment.Two populations were studied: soldiers who were recruited during 2011–2012, who belonged to birth cohorts before childhood vaccination (BCV) was introduced; and recruits from 2017, who belonged to birth cohorts after childhood vaccination (ACV) was introduced.Data on 339 BCV recruits and 295 ACV recruits were analyzed. Seropositivity was 35% in the BCV group and 68% in the ACV group (P < 0.0001). Seropositivity rates among ACV subjects enable evaluation of the vaccination program’s impact on the population. Our findings do not support discontinuation of HAV vaccination of at risk groups until further evaluation.     

规范化甲肝减毒活疫苗(LA-1株)大规模免疫的3年保护效果

目的探讨国产规范化甲肝减毒活疫苗 (LA -1株 )大规模免疫后的长期保护效果。方法将广西7个县(市)1.5～10岁儿童212985人随机分成疫苗接种组 (100735人 )和对照组 (112250人 )。疫苗组接种1针国产甲肝减毒活疫苗 (LA -1株 ,滴度106.75 TCID50)。免后1个月开始对两组观察肝炎发病情况。结果随访3年 ,对照组发现甲型肝炎病人71例 ,发病率63.25/10万 ;疫苗组发现2例 ,发病率1.99/10万 ,保护率96.85 % ,95 %可信度下限为92.44 %。结论规范化甲肝减毒活疫苗(LA -1株 )可产生满意而较为持久的保护效果。     

Immunogenicity,long term protection and safety of subcutaneous administration of hepatitis A vaccine in patients with hemophilia and other bleeding disorders: A randomized study

Hepatitis A vaccine is recommended for all individuals with hemophilia, although patients with bleeding disorders should avoid intramuscular (IM) injections. To date, only few studies showed subcutaneous (SC) route immunogenicity is comparable with the IM route. Therefore, this randomized study compared immunogenicity, long term protection and safety of hepatitis A vaccine administered by SC route with the IM route in 78 children and adults with hemophilia and other bleeding disorders. Thirty-eight patients had serology performed after first vaccine dose, determining seroconversion rates of 83.3% and 90.0% for the SC and the IM group, respectively (p = 0.5). Median IgG CO/OD value for the SC group was almost the double compared with the IM group (4.4 vs 2.6, p = 0.2). After second vaccine dose, seroconversion rates for the SC group was 97.5% and for the IM group was 97.4% (p = 1.0). Of the two patients who did not have seroconversion, interval between vaccine dose and serology was only one and two days for the SC and the IM group, respectively and in the following routine antibody dosage they presented seroconversion (100% for both groups). Median IgG CO/OD value for the SC group was greater than the IM group (72.5 vs. 58.0, p = 0.2). In a median of nine years after second vaccine dose, median IgG S/CO value for the SC group was slightly greater than the IM group (7.6 vs. 7.4, p = 0.8). There were no serious adverse events in both groups. Five (12.5%) patients of the SC group and seven (18.4%) of the IM group presented adverse events (p = 0.5). Twice as many patients of the IM group had clotting factor concentrates need for adverse events (15.8% vs. 7.5%, p = 0.3). Therefore, hepatitis A vaccine administered subcutaneously is as immunogenic, long term protective and even safer than the intramuscular route.     

Immunogenicity and safety of a tetravalent dengue vaccine and a bivalent HPV vaccine given concomitantly or sequentially in girls aged 9 to 14 years in Mexico

Dengue is endemic in several regions, and the global incidence is increasing. The recombinant, live, attenuated, tetravalent dengue vaccine (CYD-TDV) is recommended for dengue seropositive individuals ≥ 9 years. Human papillomavirus (HPV) vaccination is recommended for girls aged 9–14 years to prevent HPV infection-related cancers. This study assessed the immunogenicity and safety of a bivalent HPV (types 16 and 18) vaccine and CYD-TDV when co-administered concomitantly or sequentially.This was a Phase IIIb, randomized, open-label, multicenter study in girls aged 9–14 years in Mexico (NCT02979535). Participants were randomized 1:1 to receive three doses of CYD-TDV 6 months apart and two doses of bivalent HPV vaccine either concomitantly with, or 1 month before (sequentially), the first 2 CYD-TDV doses. Antibody levels were measured at baseline and 28-days after each vaccine dose for all participants, using an enzyme-linked immunosorbent assay for HPV-16 and HPV-18 antibodies, and a plaque reduction neutralization test for the four dengue serotypes; results are reported only for participants who were seropositive at baseline. Safety was assessed for all randomized participants throughout the study.Of the randomized participants, 305/478 (63.8%) were seropositive for dengue at baseline: 154 in the concomitant group and 151 in the sequential group. After the last HPV vaccine dose, the antibody titers for HPV were comparable in seropositive participants between treatment groups, with between group titer ratios of 0.966 for HPV-16 and 0.999 for HPV-18. After dose 3 of CYD-TDV, antibody titers were comparable for the concomitant and sequential groups across all serotypes, with between-group ratios close to 1 (serotype 1: 0.977; serotype 2: 0.911; serotype 3: 0.921; serotype 4: 0.931).CYD-TDV and a bivalent HPV vaccine administered concomitantly or sequentially in dengue seropositive girls aged 9–14 years elicited comparable immune responses with similar safety profiles.     

不同剂量甲型肝炎减毒活疫苗免疫原性与免疫持久性观察

目的：观察不同剂量的甲型肝炎（甲肝）减毒活疫苗免疫原性与免疫持久性。方法：对河北省正定县4个村166名6－8岁事先经血清检测抗－HAV阴性的易感儿童,按村分成4组,分别给予0.5、1、2及2剂经60℃3h灭活处理的甲肝减毒活疫苗（滴度为10^6.52TCID50）。并于接种后3、12、24、36及48个月采集观察对象血清,采用Abbott-IMx mEIA试剂检测血清抗－HAV。并对接种1剂、2剂活疫苗组免后4年部分血清检测中和抗体。结果：免后3个月抗体阳转率、抗体几何平均滴度（GMT）同疫苗滴度呈剂量效应关系。免疫各组抗体水平于免疫后3个月达高峰后逐年下降,12个月内下降较明显,12个月后下降缓慢。免疫后4年接种2剂活疫苗组抗体阳性率与GMT均高于接种0.5剂及1剂组。接种1、2剂活疫苗组部分经Abbott-IMx mEIA试剂检测抗－HAV阴性的血清检测中和抗体,其阳性率为60％及83％。结论：甲型肝炎减毒活疫苗的免疫原性与免疫持久性同疫苗的滴度有关,滴度为10^6.83TCID50的减毒活凤苗具有较理想的免疫原性及免疫持久性。减毒活疫苗接种后近期内不必予以加强免疫。     

Delaying the third dose of Japanese aluminum-free hepatitis A vaccine Aimmugen elicits effective immune responses against hepatitis A in adults

Inactivated aluminum-adsorbed hepatitis A vaccines such as Havrix, Vaqta, and Avaxim are commonly used worldwide. These vaccines are typically administered in a two-dose series (at 0 and 6–12 months). However, a lyophilized inactivated aluminum-free hepatitis A vaccine, Aimmugen, which is approved in Japan, is typically administered in a three-dose series (at 0, 2–4, and 24 weeks). Hence, individuals visiting endemic hepatitis A areas receive the primary two doses of Aimmugen before traveling and the third booster dose much later. It is currently uncertain whether boosting with a delayed third dose of Aimmugen is effective, or whether a new vaccination schedule should instead be initiated. Therefore, we investigated the anti-hepatitis-A viral immune response of adult travelers who received the third dose of Aimmugen more than 24 weeks after the first dose.Participants were vaccinated with the third dose of Aimmugen more than 2 years after the first two doses. Antibody titers were measured at Day 0 (prevaccination) and at 28–42 days after the third dose of Aimmugen. Twenty-nine adult participants were enrolled in the study (14 men and 15 women; mean age ± standard deviation age, 36.2 ± 8.1 years). The interval between the first two doses and the third dose was 3–14 years. The seroprotection rate (i.e., the percentage of participants with anti-hepatitis A virus antibody titers ≥ 10 mIU/mL) was 96.6 % (28/29) at Day 0 and increased to 100 % (29/29) at Days 28–42. Geometric mean concentration increased from 105 to 4,013 mIU/mL. We demonstrated that delaying the third dose of Aimmugen still elicited effective immune responses after priming with two doses of the vaccine.Trial registration: UMIN Clinical Trials Registry (UMIN-CTR): MIN000013624. Registered 03 April 2014.https://center6.umin.ac.jp/cgi-bin/ctr/ctr_view_reg.cgi?recptno=R000015906.     

Immunogenicity and estimation of antibody persistence following vaccination with an inactivated virosomal hepatitis A vaccine in adults: A 20-year follow-up study

PurposeThis was a 20-year follow-up study to assess long-term persistence of protective antibody levels against the hepatitis A virus (HAV) in healthy participants vaccinated with 2 doses of inactivated hepatitis A vaccine (Epaxal®) between 1992 and 1995.MethodsBlood samples for anti-HAV antibody concentrations were obtained during a follow-up visit 20 years after vaccination and were analyzed in parallel with samples still available from previous visits using AxSYM® HAVAB 2.0 assay.ResultsMean (SD) age of the participants was 44.71 (3.905) years at year 20 follow-up (N = 95). Participants completing 0/12-month Epaxal® immunization regimen (N = 94) had seroprotection rate of 100% (95% CI: 96.2, 100.0) with ⩾10 mIU/mL seropositivity cut-off and 98.9% (95% CI: 94.2, 100.0) with ⩾20 mIU/mL cut-off. With ⩾10 mIU/mL cut-off, the estimated median duration of protection was 77.3 years (95% CI: 71.8, 83.5) with 95% of the vaccinated participants predicted to be protected for at least 41.5 years. At ⩾20 mIU/mL cut-off, the estimated median duration of protection was 64.8 years (95% CI: 60.1, 68.4) with 95% of the vaccinated participants predicted to be protected for at least 33 years. Anti-HAV antibody geometric mean concentrations were higher in women (277.9; 95% CI: 217.7, 354.7) than in men (167.7; 95% CI: 125.2, 224.6).ConclusionThe data from this 20-year follow-up study confirm previous observations that two doses of Epaxal® provide protection against hepatitis A infection for at least 30 years in over 95% of healthy participants.     

Immunogenicity of a recombinant, yeast-derived, anti-hepatitis-B vaccine after alternative dosage and schedule vaccination in Pakistani children

A controlled, randomized trial was conducted in urban areas of Karachi and Lahore with the aim to look for ways to improve the cost-effectiveness of hepatitis B vaccination. Children under 15 years old (including neonates) were selected and screened for immunization by three regimens according to the frequency and doses of the recombinant vaccine used (Heberbiovac HB, Heber Biotec, Havana). Group A received 10 μg at 0, 1 months; group B (control) received 10 μg at 0, 1 and 2 months (standard regime), and group C received 5 μg at 0, 1 and 2 months. Antibody levels were titrated 2 months after the last dose. Cut-off for seroprotection and hyperresponse were taken as 10 and 100 IU/L, respectively. Nine hundred and ninety children were included and evaluated after discarding those positive for serological hepatitis virus infection markers. Seroprotection rates were 100, 99.7 and 99.7%, and hyperresponse was achieved by 92.7, 99.4, and 97% of the vaccinees in groups A, B, and C, respectively. The same good result was obtained in extreme ages subgroups (≤1 year and ≥10 years old). The 1-year follow up of the children from Karachi showed good persistence of seroprotection (98, 100, and 99.4%) and hyperresponse (79.7, 96.7, and 87.4%). It is concluded that it is feasible to improve the cost–benefit ratio and compliance of hepatitis B vaccination by means of a two-shots or reduced dose schedule of the vaccine employed in the trial.     

Immunogenicity of hepatitis B vaccine among hemodialysis patients: effect of revaccination of non-responders and duration of protection

Background

Hepatitis B vaccination is recommended for patients on hemodialysis, however, seroprotection after a primary vaccine series is suboptimum. Limited data are available on the effect of revaccination of non-responders and on persistence of immunity in this population.

Methods

Hepatitis B vaccine (40 μg/dose) was given to 77 susceptible patients on hemodialysis (0, 1, and 6 month schedule). Levels of hepatitis B surface antibody (anti-HBs) were tested ≥28 days after the third dose was administered, and non-responders revaccinated with an additional 3-dose series. Vaccine responders (anti-HBs ≥10 mIU/mL) were re-tested every 6 months and booster doses given as needed. Kaplan-Meier survival curve was used to estimate the probability of maintaining protective antibody level. Cox-proportional hazards models were used to assess the association between time to loss of protective antibody levels and certain explanatory variables.

Results

Overall primary vaccine-induced response was 79.2% (95% CI 68.2%, 87.3%), including 49/77 (63.6%; 95% CI 51.8%, 74.7%) patients who received the initial primary hepatitis B vaccine series and 12/21 (57.1%; 95% CI 34.4%, 77.4%) non-responders who were revaccinated with an additional series. Among weak responders (anti-HBs level 10.0-99.9 mIU/mL), protective antibody levels persisted in 44% for 12 months post-vaccination; whereas among strong responders (anti-HBs level ≥100 mIU/mL), protective antibody levels persisted in 92% for 12 months, and 68% for 24 months post-vaccination. A weak post-vaccination response increased the risk of losing protective antibody levels (adjusted hazard ratio, 9.7; 95% confidence interval, 3.5-28.5; p < 0.0001).

Conclusion

Revaccinating patients undergoing hemodialysis who do not respond to a primary vaccine series substantially increases the pool of protected patients. The threshold for defining hepatitis B vaccine-induced immunity should be revisited in this patient population to maximize the duration of protection.     

冻干甲肝减毒活疫苗安全性及免疫原性观察

目的评价国产冻干甲肝减毒活疫苗的安全性和免疫原性。方法选择部分18~24月龄健康儿童接种1剂甲肝减毒活疫苗,使用统一的"疫苗接种日记卡"观察记录疫苗接种后副反应,于免后28 d采集血清检测抗-HAVIgG。结果共接种18~24月龄健康儿童354人,14 d内副反应发生率10.73%,发热反应发生率为7.06%,未观察到严重异常反应;检测有效血清标本333份,免后28 d抗-HAV阳性率为92.79%,抗-HAV GMT为14.60 mIU/ml。结论国产冻干甲肝减毒活疫苗具有良好的安全性和免疫原性。