首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Seventy-eight children who had received three very low doses (1 or 2 microg) of Merck, Sharp and Dohme (MSD) plasma-derived vaccine (PDV) in early infancy were followed to approximately four years of age. Of the 70 who had responded to the initial course of vaccine with measurable anti-HBs, levels had fallen to below 10 mlU/ml in 38% of subjects given 1 microg doses and in 17% of those who had been given 2 microg doses. None of the children were positive for anti-HBc. Two weeks after 2 microg dose of MSD recombinant DNA (rDNA) vaccine all subjects had more than 10 mlU/ml of anti-HBs, with 90% exceeding 1,000 mlU/ml. A response to hepatitis B vaccine in infancy is followed by an effective immunological memory for several years, even if anti-HBs falls to low levels. The rDNA hepatitis B vaccine (MSD) in 2 microg doses is an effective booster following a primary course of plasma derived vaccine.  相似文献   

2.
Safety and immunogenicity of a recombinant hepatitis B vaccine   总被引:1,自引:0,他引:1  
A hepatitis B vaccine produced in yeast by recombinant DNA technology was evaluated using 5-micrograms and 10-micrograms doses in a randomized trial lasting 7 months in 110 male armed forces recruits aged 17-19 years. Results were compared to those of an identical trial of a plasma-derived vaccine. No allergic reactions were observed, and the rate of mild side effects was similar to the plasma-derived vaccine. Seroconversion rates in the first month were 60% (33/55) and 67% (37/55) with the 5-micrograms and 10-micrograms doses of the recombinant vaccine, respectively. All participants seroconverted by 3 months, and none lost antibody. These results are very similar to those for plasma-derived vaccine. Comparison of titres of antibody to hepatitis B surface antigen (anti-HBs) showed a slightly higher level with the 10-micrograms than with the 5-micrograms dose of the recombinant vaccine. Geometric mean titres of anti-HBs after the booster dose were similar in the 5-micrograms and 10-micrograms dose recombinant vaccine groups (2,620 and 2,748 IU/l, respectively) and in the 5-micrograms plasma-derived vaccine group (3,591 IU/l) but significantly higher (9,227 IU/l) with the 10-micrograms dose of the plasma-derived vaccine. These results confirm the safety and immunogenicity of the recombinant vaccine, although further study is needed on the duration of immunity.  相似文献   

3.
The immunogenicity of plasma-derived (HB Vax,MSD) and recombinant hepatitis B virus (Engerix B, SK&F) vaccines was evaluated in infants born to hepatitis B virus carrier mothers. The vaccination was carried out at 1 day, 1 month, and 6 months of age using 10 micrograms of the vaccine given intramuscularly. A total of 83/88 (94.3%) and 74/79 (93.6%) of the infants receiving the plasma-derived vaccine and yeast-derived vaccine showed antibody to hepatitis B surface antigen (anti-HBs). None of the maternal factors studied apart from the HBeAg positivity corellated with vaccine failure. The yeast-derived vaccine gives marginally lower antibody titre than the plasma-derived vaccine. The group-specific anti-"a" antibody was less than 10% of the total anti-HBsAg titre. It was observed that the vaccine alone without prior administration of hepatitis B immunoglobulin is effective in perinatal infection.  相似文献   

4.
A half dose recombinant hepatitis B vaccine (HBVax II, MSD, 5 micrograms) was investigated for efficacy in the prevention of perinatal hepatitis B virus (HBV) transmission in high risk neonates born from e-antigen positive HBsAg carrier mothers as compared to the half-standard dose regimen of plasma derived hepatitis B vaccine (HBVax, MSD, 10 micrograms). Forty infants born to carrier mothers were given hepatitis B immune globulin (HBIG) 100 IU intramuscularly immediately after birth, combined with either the recombinant or plasma derived hepatitis B vaccine. The infants were randomly divided into two groups of 20 infants each. The plasma derived vaccine (10 micrograms) was given to group I, while infants in group II received the recombinant vaccine (5 micrograms) at birth, 1 and 6 months of age. There were no statistically significant differences in the efficacy and the seroconversion rate of these two combined prophylaxis regimens. The protective efficacy rate of both kinds of HBV vaccine was found to be 94.6 and 89.2 percent in group I and group II respectively. At twelve months of age, the anti-HBs seroconversion rates were 95.0 percent in group I and 84.2 percent in group II. However, the geometric mean titres in group I (179.55 mIU/ml) was significantly higher than those in group II (42.2 mIU/ml) but the anti-HBs titre was still above protective level (10 mIU/ml) in most of the infants.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
Recombinant Hepatitis B Vaccine   总被引:1,自引:0,他引:1  
Recombinant hepatitis B vaccine Engerix B((R)) [Hep-B(Eng)] is a noninfectious subunit hepatitis B viral vaccine indicated for the active immunisation of adults, children and infants against hepatitis B virus infection. It contains hepatitis B surface antigen (HBsAg) which is produced by the yeast Saccharomyces cerevisiae by use of recombinant DNA technology. In adults and children seroprotection rates [anti-HBsAg antibody (anti-HBs) titres >/=10 IU/L] were 93 to 100% 1 month after completion of the immunisation schedule with Hep-B(Eng) [0, 1, 6-month schedule]. A more rapid immunological response has been reported with accelerated Hep-B(Eng) immunisation schedules, such as the 0, 1, 2, 12-month schedule. Hep-B(Eng) produces seroprotection rates similar to those achieved with the plasma-derived vaccines and the recombinant hepatitis B vaccine, Recombivax-HB((R)) [Hep-B(Rax)] when administered at recommended doses. In studies in Taiwanese and Thai neonates born to hepatitis B carrier mothers, seroprotection rates were >/=94% 12 months after immunisation with Hep-B(Eng) [+/- hepatitis B immunoglobulin (HBIG)] and protective efficacy was high, with 相似文献   

6.
Six hundred forty-three children, negative for markers of hepatitis B virus (HBV) infections, were given three X 2-micrograms doses of Merck, Sharp and Dohme (MSD) plasma derived hepatitis B vaccine (H-B-Vax) at monthly intervals. Twelve months after the first dose of vaccine, antibody to hepatitis B surface antigen (anti-HBs) was detected in 89% of children by radioimmunoassay (RIA) and in 83% by enzyme immunoassay (EIA). Seroconversion rates and anti-HBs titres were significantly greater in 1-4-year-olds than in older children (p less than 0.01). Eighteen children with no anti-HBs or other markers of HBV at this time were given 10 micrograms of vaccine and tested one month later. Seventeen developed anti-HBs, 12 at levels consistent with an anamnestic response. Forty-nine HBV-marker-negative children seroconverted for antibody to hepatitis B core antigen (anti-HBc) in the 8-month period before or the 12-month period following vaccination. Forty-six of these children were positive for anti-HBs, and one has been confirmed as a chronic carrier of hepatitis B surface antigen (HBsAg). Three cases of clinical hepatitis B in children have been seen in the community since the vaccination programme began. Two of these were amongst the estimated 5% of children who were not vaccinated. The third was in a vaccinee and occurred 4 1/2 months after the last dose of vaccine.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

7.
Six hundred and fifty New Zealand children from 2-12 years of age were vaccinated three times with 2 mcg intramuscular (IM) doses of Merck Sharp and Dohme plasma-derived hepatitis B vaccine (H-B-Vax), at 0, 1, and 6 months, and tested 2-3 months later for antibody to hepatitis B surface antigen (anti-HBs) by radioimmunoassay (RIA). Overall, 96.5% of the children seroconverted for anti-HBs by RIA, having levels greater than 2.1 RIA S/N units, with 91.2% having values greater than 10 S/N units. Anti-HBs levels were also determined by enzyme immunoassay (EIA), by which method a significantly better response was demonstrated in 2-4-year-olds than in older children. This study demonstrated that a satisfactory anti-HBs response was obtained using one-fifth of the recommended doses of hepatitis B vaccine.  相似文献   

8.
The immunogenicity and safety of a standard dose of 10 micrograms of a yeast derived recombinant DNA hepatitis B vaccine (B-Hepavac II) was compared with that of a reduced dose of 5 micrograms in 84 healthy adult volunteers with no previous exposure to hepatitis B. Each subject received either a 10 micrograms or 5 micrograms dose of vaccine intramuscularly at 0, 1 and 6 months. One month after the second injection of vaccine the seroconversion rate in the two groups were 85 and 86 percent respectively. Two months after the third injection 100 percent of participants had sero-converted; 95 percent of the 10 micrograms group and 91 percent of the 5 micrograms group had titres of anti-HBs greater than 10 IU/L. The geometric mean titres (GMT) of anti-HBs levels at 2, 6, 8, and 12 months were 34, 61, 811 and 188 IU/L in the 10 micrograms group and 26, 45, 836 and 304 IU/L in the 5 micrograms group respectively. Adverse effects were mild and transient. The vaccine was safe and immunogenic in the doses given. The reduced dose of 5 micrograms was as effective as the standard 10 micrograms dose.  相似文献   

9.
目的研究接受不同剂量重组酵母乙型肝炎疫苗治疗的慢乙肝患者外周血淋巴细胞对疫苗的特异性细胞免疫反应。方法选择72例6个月内无使用抗病毒治疗的慢性乙型肝炎患者按1:1:1的比例随机分为90tLg组、60tLg组、安慰剂组(0μg)。患者同时联合使用干扰素alb5MIU每周3次共24周。所有患者均停药后观察24周。在不同的时间点检测患者HBVDNA、HBeAg及肝功能,酶联免疫斑点试验(ELISPOT)法检测产生IFN-7的细胞数。结果治疗前三组患者的ELISPOT阳性率的差异无统计学意义。治疗24周时高剂量、低剂量和安慰剂组ELISPOT试验阳性的患者分别有12例、12例和7例。重组酵母乙型肝炎疫苗组(高剂量、低剂量)ELISPOT阳性率比安慰剂组明显升高,差异有统计学意义(P=0.0446)。24例ELISPOT阳性的重组酵母乙型肝炎疫苗组(高剂量、低剂量)患者中有6例产生HBVDNA转阴、7例发生HBeAg消失或转换,而7例ELISPOT阳性的安慰剂组患者均无HBVDNA转阴及HBeAg消失或转换。停药后24周,ELISPOT阳性者中。重组酵母乙型肝炎疫苗组(高剂量、低剂量)共有4例产生HBVDNA转阴、9例发生HBeAg消失或转换,而接受安慰剂治疗组均无HBVDNA转阴、仅有1例发生HBeAg转换。结论重组酵母乙型肝炎疫苗对慢性乙型肝炎患者有提高特异性T淋巴细胞功能的作用。高剂量组和低剂量组ELISPOT阳性率差异无统计学意义。  相似文献   

10.
We tested the safety and long-term immunogenicity of two of the early investigative lots of a recombinant-yeast-derived hepatitis B vaccine in immunocompetent adults. Three 10-micrograms doses of recombinant hepatitis B vaccine (Merck Sharp & Dohme Research Laboratories, West Point, PA) were administered by deltoid intramuscular injection at time 0, 1, and 6 months to 65 seronegative adult health workers. Following a complete three-injection course, 98% of vaccinees acquired anti-HBs, 97% at levels greater than 10 mlU/ml, and 95% maintained such "protective" antibody levels at 1 year. At 2 years, 93% retained antibody, but only 68% had levels greater than 10 mlU/ml. In those who responded to vaccination by achieving any detectable level of antibody, the peak geometric mean titer of anti-HBs, measured at 9 months, was 741 +/- 6 mlU/ml; the geometric mean titer fell to 348 +/- 6 at 1 year and to 66 +/- 7 at 2 years. Side effects were trivial, and levels of yeast antibody, as measured by radioimmunoassay, were not changed from prevaccine levels. No serious adverse effects were encountered, and neither type B nor non-B hepatitis occurred in any vaccine. These findings demonstrate that the recombinant yeast hepatitis B vaccine is safe and immunogenic but that 10 micrograms of the early investigative lots of the recombinant vaccine is less immunogenic than 20 micrograms of the plasma-derived vaccine. Recipients of early investigative vaccine lots should be considered for booster vaccination with currently available, more immunogenic vaccine lots.  相似文献   

11.
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)  相似文献   

12.
Summary Of the medical staff of our hospital 217 members at high risk for hepatitis B were immunized with an experimental hepatitis B vaccine and anti-HBs titers used to study the influence of two dosage schedules, age, and sex on immunogenicity. Participants were 34 years of age (mean; range, 20–61); they were divided into two groups and vaccinated three times. Group A received 42 µg HBsAg for each vaccination. Group B received 84 µg for the first and 21 µg for the second and third vaccinations. The seroconversion rate was 32.7% after the first, 78.8% after the second, and 95.7% after the third vaccination. The participants who failed to produce anti-HBs titer (3 IU/l;n=9) or whose anti-HBs titers were below 50 IU/l (n=31) were vaccinated a fourth time. Only mild side effects of injections were observed in a third of all participants, usually in the form of a sore arm.Between groups A and B there were no significant differences as far as the seroconversion rate and anti-HBs titer were concerned. Nonresponders plus low-responders accounted for 19%. Female participants produced a markedly higher anti-HBs titer than males, and the female/male ratio among non- and low-responders was 1:2; among nonresponders, 1:2.5. There was a negative correlation of the anti-HBs titer with the age of the participants. These results not only have practical consequences for revaccination policy, but also offer the opportunity to further study the genetic regulation of the immune response to a complex peptide antigen in man.Abbreviations anti-HBc antibody to hepatitis B core antigen - anti-HBe antibody to hepatitis B e antigen - anti-HBs antibody to hepatitis B surface antigen - HBsAg hepatitis B surface antigen - IU/l international units per liter - MSD Merck, Sharp, and Dohme  相似文献   

13.
A reduced dose of plasma derived hepatitis B vaccine (Hevac B) was tested for efficacy in the prevention of perinatal hepatitis B virus (HBV) transmission in high risk neonates born from e-antigen positive HBsAg carrier mothers. Forty newborn infants born of these mothers were given hepatitis B immune globulin (HBIG) 100 IU intramuscularly immediately after birth, combined with either standard or reduced doses of HBV vaccine. The infants were divided into two groups of 20 infants each. The standard dose of HBV vaccine (5 micrograms) was given to group I, while infants in group II received reduced dose (2 micrograms) at birth and at 1, 2 and 12 months of age. There was no statistically significant difference in the efficacy and antibody responses of these two combined prophylaxis regimens. The protective efficacy rate of HBV vaccine was found to be 94.0 and 93.2 percent in group I and group II, respectively. At twelve months of age, the anti-HBs seroconversion rates were 80.0 percent in group I and 86.7 percent in group II, with geometric mean titres of 84.57 mlU/ml and 78.56 mlU/ml, in group I and group II, respectively. One month after a booster at one year of age, anti-HBs could be detected in 86.7 percent of the infants in both groups. The geometric mean titres were 429.04 and 664.81 mlU/ml, in group I and group II, respectively. Anti-PreS2 antibody was detected in high titre as early as 4 months after the first dose of HBV vaccine, with a geometric mean titre of 116.30 mlU/ml and 107.97 mlU/ml, in group I and group II, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

14.
One hundred forty-four adult health care personnel (aged 18-62 years, median 33 years) considered at high risk of future HBV infection were vaccinated with a plasma-derived hepatitis B vaccine (20 micrograms HBVax at 0, 1, and 6 months) and followed-up for 2 years. Anti-HBs was present in only 6.9% prior to vaccination, and prescreening to detect this group would not have been cost-effective. At 9 months, 8.3% were nonresponders and a further 9% had anti-HBs levels less than 50 mIU/ml. Multivariate analysis showed that age was the single most important determinant of a poor response. In 47 of 52 individuals retested 2 years later, anti-HBs levels had fallen by 80% or more, and in four it had become undetectable. Response to a booster dose at this stage was excellent, with anti-HBs levels 3 months later much higher than at the end of the initial course. Additional booster doses of vaccine in two of the initial nonresponders at 14 and 22 months, respectively, also led to seroconversion. Although a significant proportion of health care workers in this study did not make a satisfactory response to the hepatitis B vaccine, later booster doses were very effective in subsequently increasing anti-HBs levels.  相似文献   

15.
A field trial of a plasma-derived hepatitis B vaccine in five rural villages in Zambia was analyzed to determine if adults in a rural African setting respond to this vaccine as well as adults in Western countries and to determine the immunogenicity of fewer than the recommended three doses; 255 residents, including 171 who were susceptible to hepatitis B, were vaccinated. Among those who received three vaccine doses, protective levels of antibody to hepatitis B surface antigen (anti-HBs) developed in 67% of adults (ages 21 to 70 years), 87% of adolescents (ages 12 to 19 years), and 100% of children (ages 0 to 11 years). The 67% of vaccinated adults who developed anti-HBs at the protective level was lower than the 96% reported among adults receiving the same vaccine at the same dose and dosage schedule in studies in Western countries. No difference was seen in the response of those receiving two doses compared with those receiving three doses among adults and adolescents, suggesting that a two-dose regimen may be acceptable in these age groups in developing countries to reduce costs and improve compliance. Use of hepatitis B vaccine in a region where prevaccination hepatitis B serologic screening was not available did not appear to increase the number of severity of adverse reactions.  相似文献   

16.
The determination of serum levels of antibodies against hepatitis B virus surface antigen (anti-HBs) after hepatitis B vaccination is currently the only simple test available to predict the decay of protection and to plan the administration of booster doses. A total of 3085 vaccine recipients of plasma-derived and recombinant vaccine have been followed for 10 years to determine the kinetics of anti-HBs production and to construct a mathematical model which could efficiently predict the anti-HBs level decline. The anti-HBs peak level was reached 68 days after the last dose of recombinant vaccine and 138 days after the last dose of plasma-derived vaccines. The age of vaccinees negatively influenced the anti-HBs levels and also the time necessary to reach the anti-HBs peak. A bilogarithmic mathematical model (log10 level, log10 time) of anti-HBs decay has been constructed on a sample of recombinant vaccine recipients and subsequently validated on different samples of recombinant or plasma-derived vaccine recipients. Age, gender, type of vaccine (recombinant or plasma-derived), number of vaccine doses (three or four) did not influence the mathematical model of antibody decay. The program can be downloaded at the site: http:@www2.stat.unibo.it/palareti/vaccine.htm . Introducing an anti-HBs determination obtained after the peak, the program calculates a prediction of individual anti-HBs decline and allows planning of an efficient booster policy.  相似文献   

17.
GenHevac B Pasteur is a recombinant hepatitis B vaccine derived from a mammalian cell line and containing HBs as well as pre-S2 antigens. Its immunogenicity was compared to that of the plasma-derived vaccine Hevac B Pasteur in a population primovaccinated 5.5 years earlier with four injections of the same plasma vaccine. The booster injection with either GenHevac or Hevac was administered to 295 subjects with residual anti-HBs titres below 500 IU/l (group 1: 0–9; group 2: 10–99; group 3: 100–499 IU/l). After four weeks, GenHevac had induced higher anti-HBs responses than Hevac in all groups, particularly among the low responders of group 1. Response to the vaccine occurred earlier with GenHevac. Mean anti-pre-S2 production was moderate in all groups for both vaccines (GenHevac: 60 IU/l; Hevac: 31 IU/l) and was not found in the 32 subjects who produced less than 100 IU/l anti-HBs. The results of the present study indicate that GenHevac is at least as immunogenic as Hevac.  相似文献   

18.
A study was conducted to investigate the immunogenicity of a recombinant DNA hepatitis B vaccine in neonates and children of HIV-infected women. Immunization against hepatitis B consisted of three 10 μg doses of the vaccine administered on a 0-, 1- and 6-month schedule. The children were followed up for an average of 11 months. Of the 118 HIV-positive neonates who participated in the study, 95 lost their HIV antibodies during the follow-up period. Most (94.2%) of the latter who completed the study responded to the vaccine. Of the 23 who remained HIV-positive, 17 completed the study and 7 produced hepatitis B antibodies. © 1995 Wiley-Liss, inc.  相似文献   

19.
One hundred and one of 255 recipients of a plasma-derived hepatitis B vaccine were evaluated in 1990, 9 years after the first vaccine dose in a study in Zambia to evaluate the efficacy of one, two, or three doses. In 1983, 2 years after the first vaccine dose, antibody to the hepatitis B surface antigen (anti-HBs) had been detectable in 90 of these 101 participants (89%). In 1990, anti-HBs was still detectable in 72 of 101 (71%), and was present at a protective level ( ≥ 10 mlU ml) in 68 of 101 (67%). Although the original vaccine study elicited a protective level of antibody in a greater percentage of children and adolescents than in adults, there were no significant differences among the three groups at 9 years. (In 1990, anti-HBs was still detectable in 52 of 70 [74%] who had had no serologic markers of the hepatitis B virus in 1981, and a protective level was detected in 47 of 70 [67%].) A protective level of anti-HBs was detected in 1990 in 26 of 36 (72%) recipients of three doses and in 23 of 31 (74%) recipients of two doses; the slightly lower prevalence among recipients of one dose (19 of 34 [56%]) was not statistically significant. However, between the years 1983–1990, hepatitis B virus infections had occurred in one of 36 (3%) of those who had been vaccinated with three doses, one of 31 (3%) vaccinated with two doses, and eight of 34 (24%) of those vaccinated with one dose (P < .02 for either two or three doses compared with one dose). These data support the long-term immunogenicity and protective efficacy of a two- or three-dose regimen of the hepatitis B vaccine in a rural African setting. © 1993 Wiley-Liss, Inc.  相似文献   

20.
Prevention and control of hepatitis B in China   总被引:39,自引:0,他引:39  
About 170 million Chinese are infected chronically with HBV and 10% suffer from chronic hepatitis. Around half a million Chinese die from hepatitis B caused hepatocellular carcinoma and endstage cirrhosis each year. From 1983 to the present, a controlled clinical trial involving 80,000 children on a universal hepatitis B vaccination programme to prevent chronic hepatitis, hepatocellular carcinoma, and endstage cirrhosis was implemented in Qidong, China. A pilot study demonstrated that the HBsAg rate reached the adult level before the fifth year of age, and neonatal vaccination with either plasma-derived or recombinant hepatitis B vaccines provided a similar 75% protective efficacy against HBV infection. The high rate of follow-up and blood tests coverage of the cohorts provided data to show 75% protection at the tenth to eleventh years of age against serum HBsAg and also against prolonged hepatic dysfunction. The strategy of controlling hepatitis B nationwide was based on the universal immunisation of newborns, beginning in cities and then the rural areas. The large-scale vaccine source was provided by domestic plants through technology transfer, first providing plasma-derived vaccine replaced completely by recombinant DNA vaccine in 1997. An official survey in 1999 using a cluster sampling of 25,878 children from 31 provinces reported an average coverage rate of three dose of hepatitis B vaccination of 70.7%, being higher in urban areas. The Ministry of Public Health of China has planned to integrate hepatitis B vaccination into the nationwide EPI program with Government-provided vaccines starting January 1, 2002.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号