不同剂量乙肝疫苗与HBIG联合免疫阻断HBV母婴传播的效果对比

目的 探讨10 μg和20 μg乙肝疫苗与HBIG联合免疫阻断HBV母婴传播的效果.方法 124例HBsAg阳性孕妇所生的婴儿随机分为两组,即10 μg乙肝疫苗组和20 μg乙肝疫苗组.婴儿于出生6h内及30 d分别注射200 IU HBIG,同时分别于出生24 h内、1个月及6个月注射3次10 μg或20 μg重组酵母乙肝疫苗.检测婴儿出生时以及1岁时血清HBV标志物.结果 两组新生儿血清HBsAg、HBeAg及抗-HBe阳性率与滴度之间差别均无统计学意义（P＞0.05）.所有新生儿血清HBV DNA水平均小于检测下限（500 U/ml）.出生12个月时,所有124例婴儿血清HBsAg和HBeAg检测结果均为阴性;血清HBV DNA水平均在检测下限以下;10 μg和20 μg乙肝疫苗组血清抗-HBs阳性率分别为90.3％和96.8％,差异无统计学意义（P＞0.05）;抗-HBs水平分别为325.5±342.2 mIU/ml和463.7±353.3 mIU/ml,后者显著高于前者（P=0.01）.而且,20 μg乙肝疫苗组产生高应答抗-HBs（＞ 100 mIU/ml）的比例显著高于10μg乙肝疫苗组（P =0.035）.结论 20 μg乙肝疫苗联合HBIG方案阻断HBV母婴传播的效果优于10 μg乙肝疫苗联合HBIG方案.     

乙型肝炎病毒母婴阻断长期效果的随访研究

目的观察乙型肝炎病毒母婴阻断长期效果,探讨HBsAg阳性孕妇生产儿童发生慢性HBV感染的相关影响因素。方法随访和收集于2004--2006年在北京地坛医院出生的HBsAg阳性母亲所生,并在出生时进行200单位乙肝免疫球蛋白（HBIG）注射和经过乙肝疫苗10μg,0、1和6个月的完整免疫接种程序的儿童静脉血,采用Abbott微粒子化学发光法检测其HBsAg、抗-HBs抗体、抗-HBc抗体,分析母婴阻断和乙肝疫苗接种的长期效果及其影响因素。结果收集和调查306名儿童年龄3—6（4．84）岁,其母亲生产时HBeAg阳性198人,HBeAg阴性92人。10（3．27％）名儿童发生慢性HBV感染。除慢性HBV感染者外,其余296名儿童,20．27％抗-HBs〈10mlU／ml;44．26％抗-HBs≥10—100mlU／ml;27．03％抗-HBs≥100～1000mlU／ml和8．45％抗-HBs≥1000mlU／m,抗-HBs保护率为79．73％（236／296）。抗-HBc阳性率为7．43％（22／296）。10例感染儿童的母亲生产时HBeAg均为阳性,HBVDNA均在10。拷贝／ml以上,其中8例超过10^8拷贝／ml。结论在进行乙肝疫苗加HBIG注射的HBV母婴传播阻断措施下,HBV母婴阻断失败和慢性H13V感染发生在HBeAg阳性和高病毒载量产妇所生婴儿,在有效阻断后仍需进行抗HBs监测并加强免疫接种。     

Reduced doses of hepatitis B immune globulin in the prevention of perinatal transmission of hepatitis B

From October 1982 to May 1983, newborn infants of 79 hepatitis B surface antigen (HBsAg)-positive women were enrolled in a study of the efficacy of hepatitis B immune globulin (HBIG) in the prophylaxis of perinatal transmission of hepatitis B virus (HBV) infection. HBIG 0.5 ml or 0.25 ml was given to the newborn within 15 minutes of birth and at 3 and 6 months. The mother-infant pairs were followed-up every 3 months for at least 9 months. Similar observations of untreated infants were used for comparison. Among infants of hepatitis B e antigen (HBeAg)-positive carrier mothers, the HBsAg carrier rates at 3 months were similar in the 0.5-ml and 0.25-ml HBIG dose groups. At 12 months the difference--17.7% of 17, 40% of 15--did not reach statistical significance, but the differences between these rates and that of the untreated control-85.7% of 35--did. Among infants of HBeAg-negative carrier mothers, HBV infection rates in both dose groups were similar to those of untreated infants. In the treated groups at 12 months about 45% of infants of HBeAg-positive mothers and 90% of infants of HBeAg-negative mothers were still negative for HBsAg and anti-HBs. Vaccination to induce active antibody is necessary to prevent postnatal infection and chronic carriage of HBV. To reduce the cost of combined passive and active hepatitis B immunoprophylaxis in children born to HBeAg-positive carrier mothers, 0.25 ml of HBIG could be used instead of the usually recommended 0.5 ml.     

Hepatitis B immunization in high risk neonates born from HBsAg positive mothers: comparison between plasma derived and recombinant DNA vaccine

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)     

Immunoprophylaxis of perinatal transmission of the hepatitis B virus: efficacy of hepatitis B immune globulin and hepatitis B vaccine in a low-prevalence area

One hundred eleven newborn infants born of Spanish hepatitis B surface antigen (HBsAg) carrier mothers were consecutively assigned to one of three treatment groups. Group A was treated with three or four doses of hepatitis B immune globulin (HBIG) in one of three different schedules. Group B received one dose of hepatitis B vaccine (Hevac-B, Pasteur) at birth and at 1, 2 and 12 months. Group C was treated with the same vaccination schedule as group B and in addition received a single dose of HBIG at birth. Comparisons were made in the 85 babies who had strictly completed the immunization schedule and had been followed for at least 12 months. The three immunization protocols were equally effective, since none of the children became a chronic HBsAg carrier or developed acute symptomatic infection. There were five transient and subclinical infections among children who received only HBIG (group A), one transient infection in group B, and one in group C. There seems to be some correlation between anti-HBs levels and degree of protection, since all transient infections in group A occurred in the subgroups who did not maintain protective antibodies during the first 6 months. Although the percentage of responders in the two vaccinated groups did not differ significantly, children who received only vaccine reached higher antibody levels than those who also received HBIG. Our results suggest that any immunization schedule able to maintain anti-HBs levels during the first 6 months of life would be useful to prevent mother-to-infant transmission of the hepatitis B virus in areas where most of the carrier women are expected to be anti-HBe positive and hence relatively less infectious.     

乙肝疫苗联合乙肝免疫球蛋白对阻断母婴垂直传播乙型肝炎病毒的临床分析

目的探讨孕妇产前用乙肝免疫球蛋白（HBIG）与乙型肝炎疫苗联合免疫阻断母婴传播的效果。方法将504例HBsAg（＋）孕妇分为A（预防组）,B（对照组）两组。A组：246名HBsAg阳性孕妇孕晚期每月分别注射基因重组型乙肝疫苗10μg、HBIG200IU（200IU/ml）,新生儿出生后采股静脉血,同时在出生后24h内注射HBIG200IU,然后在0、1、6月龄接种基因重组型乙肝疫苗,每次10μg。B组：258例产前未注射HBIG和基因重组型乙肝疫苗的HBsAg阳性孕妇,其所生新生儿在0、1、6（30μg、30μg、30μg）月龄只用基因重组型乙肝疫苗免疫。A、B两组婴儿都分别在0、3、6、9、12、24月龄静脉采血,用酶联免疫吸附试验（ELISA）检测HBV标志物,同时随访。结果A组的宫内感染率为3.25%,B组为4.16%,差异无统计学意义（χ^2=1.43,P〉0.05）。A组没有发生慢性HBV感染的婴儿,而B组中有7例婴儿发生慢性HBV感染,B组婴儿发生慢性HBV的感染率显著高于A组（χ^2=4.41,P〈0.05）。结论产前用HBIG和新生儿HBIG联合免疫可降低慢性HBV感染率,阻断宫内感染的慢性化,提高产程感染的阻断效果。     

Immunogenicity of a yeast-recombinant hepatitis B vaccine in high-risk children

Horizontal transmission of hepatitis B virus (HBV) from illicit drug users to their contacts, including young children, can be prevented by active immunization against HBV. Yeast-recombinant hepatitis B vaccines are now available for this purpose, but their potential efficacy in such high-risk contacts has not yet been evaluated. Therefore we gave 20 mcg of a recombinant yeast-derived hepatitis B vaccine to 38 children who were at high risk for HBV infection because they had been institutionalized in a community for drug users in which 8.7% of the occupants are carriers. After third dose of vaccine (at 0, 1, and 6 months), all children had anti-HBs responses with titers of 10 mIU/ml or more, with 81% showing responses greater than 1,000 mIU/ml. At 12 months, the percentage of anti-HBs-positive children was 100%, and the percentage of children with anti-HBs higher than 1,000 mIU/ml was 56%. None of the children developed HBV infection during follow-up. Hence the recombinant vaccine was immunogenic, with percentages of seroconversion and anti-HBs titers comparable with those attained in other categories of high-risk children with plasma-derived vaccines.     

Response to hepatitis B vaccine in family members of HBsAg carriers

The family members of HBsAg carriers have an increased risk of hepatitis B virus (HBV) infection. 214 subjects from 98 families with no HBV markers were randomized to receive hepatitis B vaccine: HEVAC B (Institute Pasteur) or GCC VAC (Green Cross Corporation) at 0, 1, and 5 months. Of those who completed the course, 87.8% had an anti-HBs response of greater than 10 mIU/ml at 6 months. The response rate was similar for both sexes. There was a decrease in response rate and anti-HBs titre with age. The response rate for HEVAC B was 92.5% and GCC VAC 84.3%. The offspring had comparable response to the spouses who were not blood relatives of the index carriers, but this could be related to their younger age. Discriminant analysis showed that a higher anti-HBs titre was associated with HEVAC B, younger age, and less direct relationship with the index carrier.     

Efficacy of hepatitis-B immunoglobulin and hepatitis-B vaccine in prevention of the HBsAg carrier state in newborn infants of mothers who are chronic carriers of HBsAg and HBeAg

Combined prophylaxis of perinatal transmission of hepatitis B virus (HBV) with hepatitis-B immunoglobulin (HBIG) and hepatitis-B vaccine was investigated in 40 infants born to HBeAg positive carrier mothers. The efficacy of two combined prophylaxis schedules was compared to 78 similar infants in the control group receiving no treatment, by following the HBV markers at regular intervals up to one year of age. In both schedules, the HBIG and HBV vaccine were given at birth, followed by HBV vaccine given at 30 days and 60 days (group I) or 180 days (group II) of age. The incidence of persistent HBsAg carrier in infants born to HBeAg positive carrier mothers was significantly reduced from 92.6 percent at one year of age in the control group to zero percent (group I) and 11.5 percent (group II) in the treated groups. There was no statistical significant difference in the efficacy of these two combined prophylaxis schedules. HBIG given at birth did not interfere with infant immune response to the hepatitis B vaccine. At twelve months of age, anti-HBs could be detected in 77.8 percent of infants in group I and 89.5 percent in group II with mean titre of 621.4 and 1148.0 in group I and group II respectively. It was concluded that combined prophylaxis with HBIG and hepatitis-B vaccine immediately after birth is the best method for prevention of HBV perinatal transmission from HBeAg positive carrier mothers to their infants.     

Screening of pregnant women and hepatitis B prophylaxis in newborns

Prevention of perinatal hepatitis B includes: (1) screening ol pregnant women for hepatitis B surface antigen, and (2) immunoprophylaxis of babies at risk. HBIG treatment seems to be of some efficacy in preventing the HBsAg carrier state while it permits passive active immunization to occur. The disadvantage of HBIG is that it confers only temporary immunity. Therefore, it infection does not occur, babies will still be susceptible to the virus when passively administered anti-HBs will no longerbe circulating. On the other hand, vaccine provides a long term but not immediate protection. Therefore the ideal approach in post-exposure prophylaxis is a combination of passive plus active immunization. The aim is to provide an immediate protection, with the HBIG, and a long term immunity, with the vaccine, to babies born to HBsAg carrier mothers.     

Outcomes of passive-active immunoprophylaxis given to infants of mothers infected with hepatitis B virus in Babol,Iran

BackgroundInfants born to chronic hepatitis B virus (HBV) infected mothers may be infected in spite of receiving passive-active immunoprophylaxis.ObjectivesThe purpose of this study was to assess the outcome of infants born to women actively infected by HBV.Study designFrom April 2004 to September 2009, infants born to women actively infected by HBV received hepatitis B immune globulin (HBIG) and the first dose of hepatitis B vaccine at birth. The second and third doses of HBV vaccine were administered at 1 and 6 months of age. Post-vaccination tests to detect HBsAg and anti-HBs were assessed between 12 and 15 months of age. Those who had anti-HBs titers < 10 mIU/ml received the second series of HBV vaccine.ResultsThirty-four and 201 infants were born to HBeAg-seropositive and anti-HBe-seropositive mothers, respectively. HBsAg was detected in 6 (17.6%) infants born to HBeAg-seropositive mothers and in 3 (1.5%) to anti-HBe-seropositive mothers (p = 0.0001). Anti-HBs ≥ 10 mIU/ml were achieved in 26 (76.5%) and 178 (88.6%) infants of HBeAg-seropositive and anti-HBe-seropositive mothers, respectively (p > 0.05). Twenty-two (9.4%) infants were non-responders and 11(50%) of them responded to the second series of HBV vaccine.ConclusionsThe results show that infants of HBeAg-seropositive mothers have higher risk of developing of HBV infection. Some HBsAg-seronegative infants may not respond to passive-active immunoprophylaxis and may remain at risk of HBV infection.     

Prevention of perinatal transmission of hepatitis B virus (HBV): a comparison of two prophylactic schedules

Perinatal transmission of hepatitis B virus (HBV) from HBsAg carrier mothers who were HBeAg+, antiHBe+, or negative for both HBe markers, was interrupted using either 4 doses of vaccine, or one dose of hepatitis B immunoglobulin (HBIG) at birth, combined with 4 doses of vaccine. In those infants who received HBIG at birth, the antiHBs titre was significantly higher at 1 and 2 months old, but at 6, 9, and 18 months old, there was no significant difference. Among the infants of carrier mothers who did not display HBeAg (i.e., were antiHBe+, or negative for both HBe markers), a transient subclinical infection would have been expected in around 10% had there been no intervention. No evidence of such infection was detected, and no difference in outcome was found between the two treatment groups. Amongst infants born to HBeAg+ carrier mothers, infection occurred in 1 out of 8 who had received HBIG and vaccine, and in 3 of 8 who had received vaccine only. The difference in outcome was not statistically significant, but the numbers analysed were small. The infections which occurred in spite of prophylaxis may be attributable to in utero infection, poor response to vaccine by the infant, or to the mother having a particularly high HBV-DNA level. HBIG given at birth to infants of HBeAg+ carrier mothers may enhance the protection of infants who are destined to be poor responders to vaccine.     

重组酵母乙肝疫苗对新生儿免疫效果的评价

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

Hepatitis B immunization in high risk neonates born from HBsAg and HBeAg positive mothers: comparison of standard and low dose regimens

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)     

Perinatal transmission of hepatitis B virus in Thailand

Perinatal transmission of hepatitis B virus (HBV) from asymptomatic HBsAg carrier mothers to their infants was studied in 78 mother-infant pairs by determination of HBsAg, HBeAg and anti-HBe both in the mothers and in their infants at regular intervals for those children up to the time when they reached at least one year of age. Twenty-five out of the 78 (32.1%) infants born to these mothers were HBsAg-positive 2-6 months after birth and they remained so throughout the observation period of at least one year or more. Perinatal HBV transmission occurred only in infants born to HBsAg carrier mothers who were HBeAg-positive (92.6%) but not in those born to HBsAg carrier mothers who had no detectable HBeAg. This study suggests that preventive measures against HBV transmission during the perinatal period should be taken only for infants born to HBsAg carrier mothers who are HBeAg-positive. In addition, the active immune response to HBV was studied in 75 non-HBsAg carrier infants born to HBsAg carrier mothers by determination of anti-HBs at one year of age or older. Forty-three of these infants were treated with HBIG at birth and 32 infants received no treatment. It was found that infants born to HBsAg carrier mothers who were HBeAg-positive had a better active immune response (84.2% positive for anti-HBs) than infants born to HBsAg carrier mothers who had no detectable HBeAg or anti-HBe (14.3% and 20.4% positive for anti-HBs respectively).     

乙型肝炎免疫球蛋白阻断乙型肝炎病毒母婴传播的临床研究

目的探讨乙型肝炎（乙肝）表面抗原（HBsAg）阳性孕妇及其新生儿采用乙肝免疫球蛋白（HBIG）阻断乙型肝炎病毒（HBV）母婴垂直传播的效果。方法将136例HBsAg（＋）的孕妇分为观察组（72例）和对照组（64例）,观察组孕妇于孕28、32与36周分别注射乙型肝炎免疫球蛋白（HBIG）,双阳性注射400IU,单阳性注射200IU;对照组只作随访及常规产检。两组的新生儿在出生6h内、第1、6个月时分别注射乙肝疫苗（HBvac）10μg、5μg、5μg;观察组新生儿在出生6h内臀部肌内注射HBIG 100IU。分别检测两组新生儿及6月龄婴儿血清中HBsAg、乙型肝炎表面抗体（HBsAb）及HBV DNA。结果观察组新生儿HBsAg和HBV DNA阳性率较对照组低,差异有统计学意义（P〈0．05和P〈0．01）。观察组6月龄婴儿HBsAb阳性率较对照组高,而HBV DNA阳性率较对照组低,差异也均有统计学意义（P〈0．01和P〈O．05）。结论HBsAg（＋）的孕妇应用HBIG可有效阻断HBV母婴传播,而新生儿出生时应用HBIG和HBvac联合免疫,可明显提高6月龄婴儿HBsAb阳性率。     

Quantitative analysis of HBV DNA level and HBeAg titer in hepatitis B surface antigen positive mothers and their babies: HBeAg passage through the placenta and the rate of decay in babies

It is well documented that perinatal transmission is the major cause of chronic HBV infection in China. However, the mechanisms of HBV perinatal transmission are not defined clearly. It is not known whether hepatitis B e antigen can cross the human placenta, and the rate of HBeAg decay in babies with and without HBV breakthrough has not been studied. In this study, HBV serological markers were investigated in 95 hepatitis B surface antigen positive pregnant women. These markers were also studied in the babies at birth and at the age of 6 months and 12 months. The data show that 7.4% (7/95) children were infected with HBV during the first year after birth despite receiving passive-active immunoprophylaxis with hepatitis B immune globulin and hepatitis B vaccine. The surface gene fragment of HBV DNA was cloned and sequenced following PCR amplification in 7 cases of HBsAg positive babies and their mothers. All babies had the same sequences as their mothers, although two babies also had sequences that would produce an amino acid substitution within the "a" determinant. Furthermore, we measured HBeAg titers and HBV DNA levels by using Abbott AxSYM system and LightCycler-based real-time fluorescence quantitative PCR in 54 mother-infant pairs. Thirty-three mothers were HBeAg positive, and 21 mothers were HBeAg negative. Seventy percent (23/33) of neonates from HBeAg-positive mothers were HBeAg positive at birth compared with 0% (0/21) of neonates from HBeAg negative mothers. HBeAg was present at higher titer in the birth sera of the babies with HBV breakthrough than in babies without breakthrough. HBeAg was cleared from the serum in all 19 babies without breakthrough. In 17 of these 19 babies, the HBeAg was cleared within 6 months, and in two babies clearance took 12 months. The mean serum HBV DNA level in the mothers of the 4 infants with HBV breakthrough was significantly higher than in the mothers of babies who did not become infected. In conclusion, this data suggests that HBeAg can cross the human placenta, and disappears from serum within 6 months in most babies. HBV DNA levels in hepatitis B carrier mothers are associated with the failure of HBIG and vaccine immunization, and the additional influence of transmitted HBeAg cannot be excluded.     

Field evaluation of the efficacy and immunogenicity of recombinant hepatitis B vaccine without HBIG in newborn Vietnamese infants

A study involving more than 2,000 infants was conducted in Vietnam to assess the field effectiveness and immunogenicity of recombinant hepatitis B vaccine given at birth, 1 month, 2 months, without concomitant hepatitis B immune globulin (HBIG). All received a 5 microg dose of H-B-VAX II at birth. Infants born to non-carrier mothers (Group 1; N = 1798) then received 2.5 microg doses at 1 and 2 months of age, while infants of HBeAg-negative (Group 2; N = 125) or HBeAg-positive (Group 3; N = 88) carrier mothers received 5 microg doses. No Group 1 or 2 vaccinees were infected. In Group 3, 12 (14.6%) of 82 infants did become infected (estimated efficacy 84%). 98.0-98.6% of uninfected infants who were tested for anti-HBs developed a seroprotective concentration > or = 10 IU/L. In hyperendemic Vietnam, where routine maternal screening and passive-active prophylaxis of high-risk infants with vaccine plus HBIG is not feasible, administration of vaccine alone to all newborns may control effectively HBV infection.     

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)     

Seroprevalence of Hepatitis-B infection amongst Taiwanese university students 18 years following the commencement of a national Hepatitis-B vaccination program

In Taiwan, the nation-wide Hepatitis-B virus (HB) vaccination program was first launched in July 1984 and was directed to those infants born to hepatitis B surface antigen (HBsAg) carrier mothers in Taiwan. From July 1986 onwards, all infants born in Taiwan were immunized against HB. This study examined the HB-infection status amongst students at a Taiwanese university 18 years subsequent to the implementation of universal HB vaccination. A total of 1,969 new university entrants in 2005 were grouped into 1 of 3 distinct birth cohorts according to their HB-vaccination schedule (cohort-1 students born prior to July 1, 1984; cohort-3 students born subsequent to June 30, 1986) and were examined for their serum HBsAg, antibody to hepatitis B surface antigen (anti-HBs), and antibody to hepatitis B core antigen (anti-HBc) status. Immunity arising from vaccination was defined as an anti-HBs level 10 mIU/ml. We observed a trend toward a decreasing anti-HBc-positive rate and a decreasing HBsAg carrier rate from, respectively, 26.5 and 8.7% for cohort-1 to 4.7 and 1.7% for cohort-3 students. The prevalence of students featuring seronegativity for all three HB markers increased from 12.3% for cohort-1 to 48.8% for cohort-3 individuals. Amongst the 1,695 subjects revealing seronegativity for HBsAg and anti-HBc, their anti-HBs level was analyzed according to their birth year. The prevalence of students featuring a non-protective anti-HBs level increased from 11.9% for birth-year 1984 individuals to 48.2% for birth-year 1987 students. The introduction of HB vaccine has effectively reduced the transmission of HBV infection in Taiwan, 18 years subsequent to the commencement of the universal HB-vaccination program. A "waning-off" effect of anti-HBs seropositivity acquired from the HB vaccination program has also been observed.