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.     

Inactivated hepatitis A vaccine: Reactogenicity,immunogenicity, and long-term antibody persistence

This trial evaluated the reactogenicity, kinetics of antibody induction, and long-term immunogenicity of a 720 enzyme-linked immunosorbent assay units (EL. U.) antigen dose of an inactivated hepatitis A vaccine (Havrix(tm), SmithKline Beecham Biologicals, Rixensart, Belgium). One hundred six healthy adult volunteers were enrolled to receive vaccine intramuscularly according to a 0, 1, and 6-month schedule. The vaccine was well tolerated. The most frequently reported local symptom was soreness, observed following 37.1% of all doses. Headache was the most frequently reported general symptom observed following 12.9% of documented vaccine doses. The administration of one vaccine dose induced seropositivity (anti-hepatitis A virus [HAV] ≥ 20 mlU/ml) in 91% of all vaccinees 1 month later. The second vaccine dose resulted in seropositivity of the remaining vaccinees at month 2. All subjects remained seropositive for HAV antibodies at month 6, at which time the booster vaccine dose was given. At month 7, all vaccinees had anti-HAV titres > 200 mlU/ml. Serological results obtained at months 12, 18, 24, and 36 showed that antibodies against HAV induced by the vaccine booster dose persist for at least 30 months following its administration. All 49 subjects followed up until month 36 had antibody titres ≥ 20 mlU/ml. The geometric mean titre (GMT) decreased by 60% from month 7 to month 12; between month 12 and 36, the GMT decreased by approximately 14% per period of 12 months. According to the vaccine-induced antibody kinetics and the magnitude of antibody level decrease overtime, the predicted duration of antibody persistence is estimated to be at least 20 years. © 1994 Wiley-Liss, Inc.     

Immunogenicity and safety in adults of hepatitis A virus vaccine administered as a single dose with a booster 6 months later

An inactivated vaccine against hepatitis A was administered as a single 1,440 enzyme-linked immunosorbent assay (ELISA) units dose at month 0 with a booster at month 6 to 200 subjects divided into two age groups: group 1, 20–39 years (n = 134) and group II, 40–62 years (n = 66). At day 15, the seropositivity rates were 90% and 77% in groups I and II, respectively. At month 1 the seropositivity rate was 97% in both groups. At month 6 the seropositivity rates were 94% and 88% in groups I and II, respectively. One month after the booster, at month 7, 100% in both groups had become seropositive. The vaccine was well tolerated and did not cause any severe reactions. The results indicate that a single high vaccine dose offers protection against hepatitis A virus (HAV) for at least 6 months in the majority of cases where rapid vaccination is required even in travellers of older age. A booster dose will ensure long-term protection. © 1994 Wiley-Liss, Inc.     

Safety and immunogenicity of inactivated hepatitis A vaccine in patients with chronic liver disease

The safety and immunogenicity of inactivated hepatitis A vaccine was evaluated in patients with chronic liver disease. Sixty hepatitis A virus antibody (anti-HAV) seronegative patients A virus antibody (anti-HAV) seronegative patients with chronic liver disease (56 chronic hepatitis B and four chronic hepatitis C) and from 17 to 47 years of age received a dose of 1440 ELISA units of the inactivated hepatitis A vaccine at month 0, and a booster at month 6. Anti-HAV seroconversion (⩾ 33 mlU/mL) was 57.6% (34/59) on day 15, and reached 93.2% (55/59) 1 month after primary vaccination. At month 6, the seropositivity of anti-HAV decreased before the booster to 69.0% (40/58). All vaccinees had measurable titers of anti-HAV 1 month after booster vaccination, and were still seropositive at month 12. After initial vaccination, the geometric mean titers of anti-HAV among vaccine responders were 158, 264, 74, 1309, and 409 mlU/ml at day 15 and months 1, 6, 7, and 12. Overall, 59.7% (71/119) of the vaccine doses administered were followed by mostly minor reactions. The majority of symptoms reported were local, all of which resolved within 3 days after vaccination. No significant changes in serum liver enzyme levels were detected after vaccination. Thus, an inactivated hepatitis A vaccine was safe in patients with chronic liver disease while the immune response was inferior to that observed in healthy subjects reported in a previous study. J. Med. Virol. 52:215–218, 1997. © 1997 Wiley-Liss, Inc.     

Antibody persistence and immune memory in adults, 15 years after a three-dose schedule of a combined hepatitis A and B vaccine

A combined hepatitis A and B vaccine is available since 1996. Two separate open‐label primary studies evaluated the immunogenicity and safety of this hepatitis A and B vaccine (720 EI.U of HAV and 20 µg of HBsAg) in 306 healthy subjects aged 17–43 years who received three doses of the vaccine following a 0, 1, and 6 months schedule. These subjects were followed up annually for the next 15 years to evaluate long‐term persistence of anti‐HAV and anti‐HBs antibodies. The subjects whose antibody concentrations fell below the cut‐offs between Year 11 and Year 15 (anti‐HAV: <15 mIU/ml; anti‐HBs: <10 mIU/ml) were offered an additional dose of the appropriate monovalent hepatitis A and/or B vaccine. In subjects who received the additional vaccine dose, a blood sample was collected 1 month after vaccination. At the Year 15 time point, all subjects in Study A and Study B were seropositive for anti‐HAV antibodies and 89.3% and 92.9% of subjects in the respective studies had anti‐HBs antibody concentrations ≥10 mIU/ml. Four subjects (two in each study) received an additional dose of monovalent hepatitis B vaccine and mounted anamnestic responses to vaccination. No vaccine‐related serious adverse events were reported. This study confirms the long‐term immunogenicity of the three‐dose regimen of the combined hepatitis A and B vaccine, as eliciting long‐term persistence of antibodies and immune memory against hepatitis A and B for up to at least 15 years after a primary vaccination. J. Med. Virol. 84:11–17, 2011. © 2011 Wiley Periodicals, Inc.     

Immunogenicity and safety of a new inactivated hepatitis a vaccine in a comparative study

A multicentre, controlled, randomised, open, comparative trial including 839 healthy adult volunteers was carried out in order to compare the immunogenicity and reactogenicity of two vaccines against hepatitis A virus (HAV) during primary immunization and after booster injection. The first vaccine was produced by Pasteur Mérieux (PM), and the second vaccine by Smith-Kline Beecham (SKB). The vaccination schedule consisted of 2 doses (months 0, 6) for PM and 3 doses (months 0, 1, and 6) for SKB. Two weeks after the first dose, the seroconversion rates among initially HAV seronegative subjects (n = 608) were 93.4% and 76.1% for the PM and SKB vaccines, respectively, the corresponding geometric mean titres (GMTs) were 59.0 mlU/ml versus 30.8 mlU/ml (modified RIA HAVAB assay, Abbott Laboratories). Two months after the beginning of immunization (one dose versus two doses) the GMTs were 138.4 and 161.6 mlU/ml, respectively. At month 7, the seroconversion rates were 100% for both vaccines, and the GMTs were 4, 189 and 3, 163 mlU/ml, respectively. After the first dose of vaccine, 24.6% and 19.6% of the PM and SKB vaccinees reported local reactions. The rates for systemic reactions were 27.2% and 25.0%, respectively. Lower rates for local and systemic reactions were seen after booster injections and statistical differences were not observed between the two vaccines. The study also demonstrated that vaccination was as well tolerated in subjects with anti-HAV antibodies as in HAV seronegative subjects. Logistic regression analysis revealed a significant vaccine effect on seroconversion rates only at week 2 (P<10^?4). The same conclusions were drawn from the analysis of GMT by multivariate regression. When both times (week 2 and week 8) were analysed together, a statistically significant effect of interaction between time and vaccine was observed, indicating that the kinetics of antibody responses were different. © 1995 Wiley-Liss, Inc.     

HBsAg阳性儿童和健康儿童对国产甲型肝炎灭活疫苗免疫原性和安全性的观察

目的：观察HBsAg阳性儿童对国产甲型肝炎灭活疫苗的免疫原性和安全性。方法：随机选取121名1－10岁健康儿童和10名同龄的HBsAg阳性儿童，抗－HAV均阴性，接种唐山怡安生物工程有限公司研制的甲型肝炎灭活疫苗。接种剂量为500U／剂和1000U／剂两组，免疫程序为0和6个月，并在初免后30d，第二针后30和180d用ELISA方法检测抗－HAV。结果：HBsAg阳性儿童和健康儿童接种500U／剂和1000U／剂甲型肝炎灭活疫苗后抗体阳转率均为100％。第二针免疫后30d抗体平均几何滴度500U／剂组分别为4684．9mIU和4535．6mIU；1000U／剂组分别为5399．8mIU和7347．1mIU。二者比较差异无显著性，免疫后亦未见异常反应，初免后1年抗体水平仍然很高。结论：HBsAg阳性儿童接种国产甲型肝炎灭活疫苗具有良好的免疫应答，同时也是安全的。     

Modelling long-term persistence of hepatitis B antibodies after vaccination

Antibody response to hepatitis B vaccination was measured in 97 institutionalized, mentally handicapped patients after a 0-, 1-, 6-month vaccination schedule. Two groups were formed at month 7 according to the antibody response, which determined whether they needed an additional vaccine dose at month 12, to achieve an antibody titre of 100 IU/liter. All residents were followed up yearly for the first 5 years, after which, they received another booster dose. Another blood sample was taken 11 years after the start of the program. A linear mixed-regression model was used to analyze the data. Random and fixed effects were included to determine the generally known risk factors and the still unknown individual characteristics that influence the titre of hepatitis B surface antibodies (anti-HBs). The mean anti-HBs titre was a function of time, type of mental retardation (Down's syndrome or other types of mental retardation), the use of antiepileptic drugs, and the additional booster at month 12. The immediate and vigorous response of the immune system to booster vaccination shows that the immunologic memory is good after primary vaccination. For the maintenance of protection, the recommendation for mentally retarded patients in institutions is vaccination of all seronegative residents as well as new entrants, after which, no additional boosters will be necessary. J. Med. Virol. 57:100–103, 1999. © 1999 Wiley-Liss, Inc.     

Accelerated schedule of hepatitis B vaccination in patients with hemophilia

Early development of immunity after hepatitis B vaccination is particularly important for patients such as hemophiliacs, at high risk for acquiring hepatitis B from potentially infectious plasmaderived concentrates. The purpose of this study was to evaluate whether or not protective antibody titers could be achieved quickly and maintained in hemophiliacs by an accelerated vaccination schedule. A yeast-recombinant hepatitis B vaccine (Engerix B, SKF Ritt) was given subcutaneously in the deltoid region and repeated 2 and 6 weeks later to 85 hemophiliacs negative for hepatitis B virus (HBV) markers. After the first 22 patients had been enrolled, a modification of the schedule involving a fourth booster dose 24 weeks after the first dose of vaccine was applied to the next 63 consecutive vaccinees. Fifty-three percent of vaccinees had antibody titers to hepatitis B surface antigen (anti-HBs≥ 10 mlU/ml) by week 6, even though the mean titers of anti-HBs were somewhat lower than those achieved historically in normal individuals. The protection rate had increased to 87% by week 10, one month after the third dose of vaccine, and to 93% by week 24. One year after starting vaccination, the rate for the vaccinees who did not receive the fourth booster dose was 71%, and 96% for those who did receive the fourth dose, with only 2 patients not responding despite the booster dose. It is concluded that even though the accelerated schedule of immunization produced rapidly high rates of protective antibody titers, a booster dose is required to obtain higher titers and provide more persistent immunity.     

Immunological efficacy of a three-dose schedule of hepatitis A vaccine in HIV-infected adults: HEPAVAC study

BACKGROUND: The immunogenicity of vaccines, including vaccine against hepatitis A virus (HAV), is impaired in patients with HIV infection, requiring revised immunization regimens. METHODS: We evaluated the immunological efficacy and safety of a 3-dose schedule of hepatitis A vaccine in HIV-infected adults. HAV-seronegative HIV-infected adults were randomized to receive either 3 doses of 1440 UI of hepatitis A vaccine (HAVRIX; GlaxoSmithKline, Marly le Roi, France) at weeks 0, 4, and 24 (46 patients) or 2 doses 24 weeks apart (49 patients). RESULTS: At week 28, seroconversion, defined as an anti-HAV antibody >or=20 mIU/mL, occurred in 82.6% and 69.4% of patients in the 3-dose and the 2-dose group, respectively (P = 0.13, intent-to-treat analysis, missing data = nonresponder), and in 88.4% and 72.3% of patients in the 3-dose and the 2-dose group, respectively (P = 0.06, observed analysis). Only 37.9% of patients experienced seroconversion after 1 vaccine dose (intent-to-treat analysis). Anti-HAV antibody geometric mean titers were 323 and 132 mIU/mL in the 3-dose group and 138 and 67 mIU/mL in the 2-dose group, respectively, 28 (P = 0.03) and 72 weeks (P = 0.05) after the first vaccine dose. There were no serious adverse events associated with the vaccine. Multivariate analysis showed no treatment group effect but indicated that absence of tobacco smoking (odds ratio = 2.92, 95% confidence interval: 1.07 to 7.97; P = 0.04) was an independent predictor of response to HAV vaccine. CONCLUSIONS: In HIV-infected adults, immunogenicity of hepatitis A vaccine is poor. Three doses of vaccine were safe and increased antibody titers.     

Different HBs antibody versus lymphoproliferative responses after application of a monovalent (hepatitis B) or combined (hepatitis A + hepatitis B) vaccine

BACKGROUND: The aim of the study was to evaluate a possible adjuvanticity of simultaneous hepatitis A (HAV) vaccination for the development of HBs-specific antibodies and lymphoproliferative responses in prophylactic immunization with hepatitis B (HBV). METHODS: Thirty-nine volunteers were vaccinated (schedule: 0/1/6 months) either with a bivalent HAV/HBV (18 individuals) or with HBV (recombinant HBs-antigen) vaccine alone (21 individuals). Anti-HBs antibody titers and lymphoproliferative responses as consequence of stimulation of peripheral blood mononuclear cells (PBMC) with HBs were evaluated and compared between the two groups before second vaccination, before and 1 month after booster. RESULTS: Geometric mean titers were higher at all time points in the group treated with the combined vaccine. On the other hand, after the booster injection, HBs-induced stimulation indices in PBMC were higher in the group vaccinated with HBs alone. Neither the difference in antibody titers nor in proliferative responses reached the level of statistical significance. Interestingly, the inverse relation between cellular proliferation and antibodies was significant, indicating that cellular reactivity is not in all cases a useful marker to evaluate the intensity of the induced immunity. CONCLUSIONS: The magnitude of the T-lymphocyte response may eventually not be decisive for the subsequent antibody response. Both vaccination strategies led to a cellular and humoral immune response and resulted in protective levels of HBs-specific antibodies.     

Influence of vaccination schedules and host factors on antibody response following hepatitis B vaccination

In a prospective multicentre trial, the influence of schedule, compliance, age, sex and weight on the antibody response to hepatitis B vaccination was investigated. Comparison of the vaccination schedules 0, 1, 6 months (group 1; n=143) and 0, 1, 2, 12 months (group 2; n=141) was performed in months 3, 7 and 12. In addition, the antibody response was compared one month after the third and one and six months after the last vaccination. Seroprotection rates (anti-HB_S>10 IU/l) and antibody titres, given as geometric means (GMTs), were higher in group 1 at month 12 as well as one month after completion of three immunizations. More vaccinees of group 2, however, showed seroprotection at month 3 with higher GMTs. In addition, GMTs in group 2 were higher both one month and six months after the last vaccine dose. Determination of parallel corrected correlation factors demonstrated that age was the most important single factor, followed by body weight and sex. However, no more than 3 % of the variation in the GMT can be explained by the influence of age. Due to decreased compliance with the four-dose schedule with a drop-out rate of approximately 10 % of the vaccinees, the total percentage of initial vaccinees who in the end developed protective antibody levels was higher in the 0, 1, 6 months schedule. Thus, it can be concluded that subjects likely to comply will benefit from the 0, 1, 2, 12 months schedule as more rapid protection is obtained and the higher antibody levels after the booster vaccination at month 12 provide longer protection. However, vaccinees whose compliance might be questionable over a period of 12 months, should be selected for the vaccination 0, 1, 6 months schedule as compliance is at a higher level over this period and advantage can be taken of the booster effect of the third dose given in month 6.     

接种3剂甲肝减毒活疫苗8年的免疫学效果

目的 观察接种3剂甲肝减毒活疫苗8年抗体持久性,并与1针法进行了比较.方法 对农村1～7岁HAV易感儿童110人,接种1剂甲型肝炎减毒活疫苗作为B组,选其中一个自然村的42名易感儿童作为A组,按0、2、6个月程序接种3剂疫苗,分别于免疫后1、2、6 7 8、12、24、36和96个月采集血清标本,检测抗-HAV总抗体.结果 B组接种甲肝减毒活疫苗后2～3个月,抗-HAV阳转率和几何平均浓度(GMC)达到高峰,分别为92.2%和126.2 mIU/ml,然后开始随时间下降.与之相比,按照0、2、6个月程序免疫的A组,抗体阳转率在第二针后即达100%,第三针后GMC达高峰,为2739 mIU/ml,A组的近期免疫效果甚至优于灭活疫苗;36～96个月B组的抗-HAV阳转率和GMC分别为75%～71%和80～89 mIU/ml;与之相比,A组36～96个月的抗-HAV阳转率和GMC分别为100%和918.2～480.6 mIU/ml,显著高于B组.结论 接种3剂甲肝减毒活疫苗近期、远期免疫效果均高于一针法,三针法加强免疫取得了良好的免疫学效果,抗体持久性和预防效果有待于进一步观察.     

接种3剂甲肝减毒活疫苗8年的免疫学效果

目的 观察接种3剂甲肝减毒活疫苗8年抗体持久性,并与1针法进行了比较.方法 对农村1～7岁HAV易感儿童110人,接种1剂甲型肝炎减毒活疫苗作为B组,选其中一个自然村的42名易感儿童作为A组,按0、2、6个月程序接种3剂疫苗,分别于免疫后1、2、6 7 8、12、24、36和96个月采集血清标本,检测抗-HAV总抗体.结果 B组接种甲肝减毒活疫苗后2～3个月,抗-HAV阳转率和几何平均浓度(GMC)达到高峰,分别为92.2%和126.2 mIU/ml,然后开始随时间下降.与之相比,按照0、2、6个月程序免疫的A组,抗体阳转率在第二针后即达100%,第三针后GMC达高峰,为2739 mIU/ml,A组的近期免疫效果甚至优于灭活疫苗;36～96个月B组的抗-HAV阳转率和GMC分别为75%～71%和80～89 mIU/ml;与之相比,A组36～96个月的抗-HAV阳转率和GMC分别为100%和918.2～480.6 mIU/ml,显著高于B组.结论 接种3剂甲肝减毒活疫苗近期、远期免疫效果均高于一针法,三针法加强免疫取得了良好的免疫学效果,抗体持久性和预防效果有待于进一步观察.     

Immunogenicity and protective efficacy of low dose recombinant DNA hepatitis B vaccine in normal and high-risk neonates.

A low dose of recombinant DNA hepatitis B vaccine (HB-VAX II, MSD) was tested for efficacy in the prevention of perinatal hepatitis B virus (HBV) transmission in normal and high-risk neonates born from HBsAg carrier mothers. A dose of 2.5 micrograms recombinant vaccine was injected intramuscularly at 0, 1, 2 and 12 months of age to 30 newborns from HBsAg negative mother (group I), 30 from HBeAg negative/HBsAg carrier mother (group II) and 30 from HBeAg positive/HBsAg carrier mother (group III). The incidence of persistent HBsAg carrier infants at 13 months of age was 0, 0, and 30.4 percent in groups I, II and III, respectively. The protective efficacy in high risk infants in group III was 65.7 percent. The seroconversion at month 4, after the third dose of vaccination was 96.3, 95.7 and 100 percent in group I, group II and group III, respectively. After a booster dose of vaccination at 12 months of age, the seroconversion rose to 100 percent at month 13 in all three groups. The geometric mean titer (GMT) of anti-HBs antibody at 13 months of age were 2,092, 1,657 and 1,938 mIU/ml in group I, group II and group III, respectively. It is concluded that the low dose (2.5 micrograms) recombinant hepatitis B vaccine using alone is effective in prevention of perinatal HBV transmission in low risk infants (groups I and II), but it is less effective in high risk infants (group III).(ABSTRACT TRUNCATED AT 250 WORDS)     

接种3剂甲肝减毒活疫苗8年的免疫学效果

目的 观察接种3剂甲肝减毒活疫苗8年抗体持久性,并与1针法进行了比较.方法 对农村1～7岁HAV易感儿童110人,接种1剂甲型肝炎减毒活疫苗作为B组,选其中一个自然村的42名易感儿童作为A组,按0、2、6个月程序接种3剂疫苗,分别于免疫后1、2、6 7 8、12、24、36和96个月采集血清标本,检测抗-HAV总抗体.结果 B组接种甲肝减毒活疫苗后2～3个月,抗-HAV阳转率和几何平均浓度(GMC)达到高峰,分别为92.2%和126.2 mIU/ml,然后开始随时间下降.与之相比,按照0、2、6个月程序免疫的A组,抗体阳转率在第二针后即达100%,第三针后GMC达高峰,为2739 mIU/ml,A组的近期免疫效果甚至优于灭活疫苗;36～96个月B组的抗-HAV阳转率和GMC分别为75%～71%和80～89 mIU/ml;与之相比,A组36～96个月的抗-HAV阳转率和GMC分别为100%和918.2～480.6 mIU/ml,显著高于B组.结论 接种3剂甲肝减毒活疫苗近期、远期免疫效果均高于一针法,三针法加强免疫取得了良好的免疫学效果,抗体持久性和预防效果有待于进一步观察.     

接种3剂甲肝减毒活疫苗8年的免疫学效果

目的 观察接种3剂甲肝减毒活疫苗8年抗体持久性,并与1针法进行了比较.方法 对农村1～7岁HAV易感儿童110人,接种1剂甲型肝炎减毒活疫苗作为B组,选其中一个自然村的42名易感儿童作为A组,按0、2、6个月程序接种3剂疫苗,分别于免疫后1、2、6 7 8、12、24、36和96个月采集血清标本,检测抗-HAV总抗体.结果 B组接种甲肝减毒活疫苗后2～3个月,抗-HAV阳转率和几何平均浓度(GMC)达到高峰,分别为92.2%和126.2 mIU/ml,然后开始随时间下降.与之相比,按照0、2、6个月程序免疫的A组,抗体阳转率在第二针后即达100%,第三针后GMC达高峰,为2739 mIU/ml,A组的近期免疫效果甚至优于灭活疫苗;36～96个月B组的抗-HAV阳转率和GMC分别为75%～71%和80～89 mIU/ml;与之相比,A组36～96个月的抗-HAV阳转率和GMC分别为100%和918.2～480.6 mIU/ml,显著高于B组.结论 接种3剂甲肝减毒活疫苗近期、远期免疫效果均高于一针法,三针法加强免疫取得了良好的免疫学效果,抗体持久性和预防效果有待于进一步观察.     

接种3剂甲肝减毒活疫苗8年的免疫学效果

目的 观察接种3剂甲肝减毒活疫苗8年抗体持久性,并与1针法进行了比较.方法 对农村1～7岁HAV易感儿童110人,接种1剂甲型肝炎减毒活疫苗作为B组,选其中一个自然村的42名易感儿童作为A组,按0、2、6个月程序接种3剂疫苗,分别于免疫后1、2、6 7 8、12、24、36和96个月采集血清标本,检测抗-HAV总抗体.结果 B组接种甲肝减毒活疫苗后2～3个月,抗-HAV阳转率和几何平均浓度(GMC)达到高峰,分别为92.2%和126.2 mIU/ml,然后开始随时间下降.与之相比,按照0、2、6个月程序免疫的A组,抗体阳转率在第二针后即达100%,第三针后GMC达高峰,为2739 mIU/ml,A组的近期免疫效果甚至优于灭活疫苗;36～96个月B组的抗-HAV阳转率和GMC分别为75%～71%和80～89 mIU/ml;与之相比,A组36～96个月的抗-HAV阳转率和GMC分别为100%和918.2～480.6 mIU/ml,显著高于B组.结论 接种3剂甲肝减毒活疫苗近期、远期免疫效果均高于一针法,三针法加强免疫取得了良好的免疫学效果,抗体持久性和预防效果有待于进一步观察.     

接种3剂甲肝减毒活疫苗8年的免疫学效果

目的 观察接种3剂甲肝减毒活疫苗8年抗体持久性,并与1针法进行了比较.方法 对农村1～7岁HAV易感儿童110人,接种1剂甲型肝炎减毒活疫苗作为B组,选其中一个自然村的42名易感儿童作为A组,按0、2、6个月程序接种3剂疫苗,分别于免疫后1、2、6 7 8、12、24、36和96个月采集血清标本,检测抗-HAV总抗体.结果 B组接种甲肝减毒活疫苗后2～3个月,抗-HAV阳转率和几何平均浓度(GMC)达到高峰,分别为92.2%和126.2 mIU/ml,然后开始随时间下降.与之相比,按照0、2、6个月程序免疫的A组,抗体阳转率在第二针后即达100%,第三针后GMC达高峰,为2739 mIU/ml,A组的近期免疫效果甚至优于灭活疫苗;36～96个月B组的抗-HAV阳转率和GMC分别为75%～71%和80～89 mIU/ml;与之相比,A组36～96个月的抗-HAV阳转率和GMC分别为100%和918.2～480.6 mIU/ml,显著高于B组.结论 接种3剂甲肝减毒活疫苗近期、远期免疫效果均高于一针法,三针法加强免疫取得了良好的免疫学效果,抗体持久性和预防效果有待于进一步观察.     

接种3剂甲肝减毒活疫苗8年的免疫学效果

目的 观察接种3剂甲肝减毒活疫苗8年抗体持久性,并与1针法进行了比较.方法 对农村1～7岁HAV易感儿童110人,接种1剂甲型肝炎减毒活疫苗作为B组,选其中一个自然村的42名易感儿童作为A组,按0、2、6个月程序接种3剂疫苗,分别于免疫后1、2、6 7 8、12、24、36和96个月采集血清标本,检测抗-HAV总抗体.结果 B组接种甲肝减毒活疫苗后2～3个月,抗-HAV阳转率和几何平均浓度(GMC)达到高峰,分别为92.2%和126.2 mIU/ml,然后开始随时间下降.与之相比,按照0、2、6个月程序免疫的A组,抗体阳转率在第二针后即达100%,第三针后GMC达高峰,为2739 mIU/ml,A组的近期免疫效果甚至优于灭活疫苗;36～96个月B组的抗-HAV阳转率和GMC分别为75%～71%和80～89 mIU/ml;与之相比,A组36～96个月的抗-HAV阳转率和GMC分别为100%和918.2～480.6 mIU/ml,显著高于B组.结论 接种3剂甲肝减毒活疫苗近期、远期免疫效果均高于一针法,三针法加强免疫取得了良好的免疫学效果,抗体持久性和预防效果有待于进一步观察.