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

Comparative efficacy and safety of pharmacologic interventions to prevent mother-to-child transmission of hepatitis B virus: a systematic review and network meta-analysis

OBJECTIVE

This study investigated the efficacy and safety of pharmacologic interventions to prevent vertical transmission of the hepatitis B virus.

DATA SOURCES

Medline, Cochrane, and Scopus databases were searched up to October 28, 2020.

STUDY ELIGIBILITY CRITERIA

All randomized controlled trials reporting vertical hepatitis B virus transmission with pharmacologic intervention were included.

METHODS

Risk of bias was assessed using the Cochrane Risk-of-Bias tool, version 2. Treatment efficacy was estimated using stratified network meta-analysis on the basis of maternal hepatitis B envelope antigen status.

RESULTS

Nineteen studies were included for mothers positive for hepatitis B surface and envelope antigens. Pooling indicated that a combination of hepatitis B vaccination and hepatitis B immunoglobulin in infants significantly reduced transmission risk compared with vaccination alone, with a risk ratio of 0.52 (95% confidence interval; 0.30-0.91). Only the addition of maternal tenofovir disoproxil fumarate, but not telbivudine, lamivudine, or maternal hepatitis B immunoglobulin further reduced transmission risk compared with a combination of hepatitis B vaccination and hepatitis B immunoglobulin in infants, with a pooled risk ratio of 0.10 (0.03-0.35). Twelve studies conducted in mothers with hepatitis B surface antigen positivity and mixed, unknown, or negative hepatitis B envelope antigen status provided limited evidence to suggest that maternal hepatitis B immunoglobulin combined with hepatitis B vaccination and immunoglobulin in infants was the likely best treatment, but this failed to reach statistical significance compared with a combination of hepatitis B vaccination and immunoglobulin in infants. Similarly, infant hepatitis B immunoglobulin, added to vaccination, likely provides additional benefit but failed to reach statistical significance.

CONCLUSION

A combination of hepatitis B vaccination and immunoglobulin in infants is the cornerstone for prevention of vertical transmission for mothers positive for both hepatitis B surface and envelope antigens. The addition of maternal tenofovir to this infant combination regimen was considered the likely most effective treatment. For infants of mothers with hepatitis B surface antigen positivity and mixed, unknown, or negative hepatitis B envelop antigen status, no additional agents provided further benefit beyond hepatitis B vaccination alone.

Prevention of hepatitis B mother-to-child transmission in Namibia: A cost-effectiveness analysis

Despite access to a safe and effective vaccine, mother-to-child transmission (MTCT) of hepatitis B virus (HBV) persists in Africa. This is of concern since perinatally-infected infants are at highest risk of developing hepatocellular carcinoma, a life-threatening consequence of chronic HBV infection. While tools to prevent HBV MTCT are available, the cost implications of these interventions need consideration prior to implementation. A Markov model was developed to determine the costs and health outcomes of (1) universal HBV birth dose (BD) vaccination, (2) universal BD vaccination and targeted hepatitis B immunoglobulin (HBIG), (3) maternal antiviral prophylaxis using sequential HBV viral load testing added to HBV BD vaccination and HBIG, and (4) maternal antiviral prophylaxis using sequential HBeAg testing combined with HBV BD vaccination and HBIG. Health outcomes were assessed as the number of paediatric infections averted and disability-adjusted life years (DALYs) averted. Primary cost data included consumables, human resources, and hospital facilities. HBV epidemiology, transitions probabilities, disability weights, and the risks of HBV MTCT were extracted from the literature. Incremental cost-effectiveness ratios (ICERs) were calculated to compare successive more expensive interventions to the previous less expensive one. One-way sensitivity analyses were conducted to test the robustness of the model's outputs. At the Namibian cost/DALY averted threshold of US$3 142, the (1) BD vaccination + targeted HBIG, and (2) maternal antiviral prophylaxis with sequential HBeAg testing interventions were cost-effective. These interventions had ICERs equal to US$1909.03/DALY and US$2598.90/DALY averted, respectively. In terms of effectiveness, the maternal antiviral prophylaxis with sequential HBeAg testing intervention was the intervention of choice. The analysis showed that elimination of HBV MTCT is achievable using maternal antiviral prophylaxis with active and passive immunization. There is an urgent need for low cost diagnostic tests to identify those women who will most benefit from drug therapy to attain this laudable goal.

Hepatitis B immunoglobulin during pregnancy for prevention of mother-to-child transmission of hepatitis B virus

BACKGROUND

Hepatitis is a viral infection of the liver. It is mainly transmitted between people through contact with infected blood, frequently from mother to baby in-utero. Hepatitis B poses significant risk to the fetus and up to 85% of infants infected by their mothers at birth develop chronic hepatitis B virus (HBV) infection. Hepatitis B immunoglobulin (HBIG) is a purified solution of human immunoglobulin that could be administered to the mother, newborn, or both. HBIG offers protection against HBV infection when administered to pregnant women who test positive for hepatitis B envelope antigen (HBeAg) or hepatitis B surface antigen (HBsAg), or both. When HBIG is administered to pregnant women, the antibodies passively diffuse across the placenta to the child. This materno-fetal diffusion is maximal during the third trimester of pregnancy. Up to 1% to 9% infants born to HBV-carrying mothers still have HBV infection despite the newborn receiving HBIG plus active HBV vaccine in the immediate neonatal period. This suggests that additional intervention such as HBIG administration to the mother during the antenatal period could be beneficial to reduce the transmission rate in utero.

OBJECTIVES

To determine the benefits and harms of hepatitis B immunoglobulin (HBIG) administration to pregnant women during their third trimester of pregnancy for the prevention of mother-to-child transmission of hepatitis B virus infection.

SEARCH METHODS

We searched the The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, Science Citation Index Expanded (Web of Science), SCOPUS, African Journals OnLine, and INDEX MEDICUS up to June 2016. We searched ClinicalTrials.gov and portal of the WHO International Clinical Trials Registry Platform (ICTRP) in December 2016.

SELECTION CRITERIA

We included randomised clinical trials comparing HBIG versus placebo or no intervention in pregnant women with HBV.

DATA COLLECTION AND ANALYSIS

Two authors extracted data independently. We analysed dichotomous outcome data using risk ratio (RR) and continuous outcome data using mean difference (MD) with 95% confidence intervals (CI). For meta-analyses, we used a fixed-effect model and a random-effects model, along with an assessment of heterogeneity. If there were statistically significant discrepancies in the results, we reported the more conservative point estimate. If the two estimates were equal, we used the estimate with the widest CI as our main result. We assessed bias control using the Cochrane Hepato-Biliary Group suggested bias risk domains and risk of random errors using Trial Sequential Analysis (TSA). We assessed the quality of the evidence using GRADE.

MAIN RESULTS

All 36 included trials originated from China and were at overall high risk of bias. The trials included 6044 pregnant women who were HBsAg, HBeAg, or hepatitis B virus DNA (HBV-DNA) positive. Only seven trials reported inclusion of HBeAg-positive mothers. All 36 trials compared HBIG versus no intervention. None of the trials used placebo.Most of the trials assessed HBIG 100 IU (two trials) and HBIG 200 IU (31 trials). The timing of administration of HBIG varied; 30 trials administered three doses of HBIG 200 IU at 28, 32, and 36 weeks of pregnancy. None of the trials reported all-cause mortality or other serious adverse events in the mothers or babies. Serological signs of hepatitis B infection of the newborns were reported as HBsAg, HBeAg, and HBV-DNA positive results at end of follow-up. Twenty-nine trials reported HBsAg status in newborns (median 1.2 months of follow-up after birth; range 0 to 12 months); seven trials reported HBeAg status (median 1.1 months of follow-up after birth; range 0 to 12 months); and 16 trials reported HBV-DNA status (median 1.2 months of follow-up; range 0 to 12 months). HBIG reduced mother-to-child transmission (MTCT) of HBsAg when compared with no intervention (179/2769 (6%) with HBIG versus 537/2541 (21%) with no intervention; RR 0.30, TSA-adjusted CI 0.20 to 0.52; I² = 36%; 29 trials; 5310 participants; very low quality evidence). HBV-DNA reduced MTCT of HBsAg (104/1112 (9%) with HBV-DNA versus 382/1018 (38%) with no intervention; RR 0.25, TSA-adjusted CI 0.22 to 0.27; I² = 84%; 16 trials; 2130 participants; low quality evidence). TSA supported both results. Meta-analysis showed that maternal HBIG did not decrease HBeAg in newborns compared with no intervention (184/889 (21%) with HBIG versus 232/875 (27%) with no intervention; RR 0.68, TSA-adjusted CI 0.04 to 6.37; I² = 90%; 7 trials; 1764 participants; very low quality evidence). TSA could neither support nor refute this observation as data were too sparse. None of the trials reported adverse events of the immunoglobulins on the newborns, presence of local and systemic adverse events on the mothers, or cost-effectiveness of treatment.

AUTHORS' CONCLUSIONS

Due to very low to low quality evidence found in this review, we are uncertain of the effect of benefit of antenatal HBIG administration to the HBV-infected mothers on newborn outcomes, such as HBsAg, HBV-DNA, and HBeAg compared with no intervention. The results of the effects of HBIG on HBsAg and HBeAg are surrogate outcomes (raising risk of indirectness), and we need to be critical while interpreting the findings. We found no data on newborn mortality or maternal mortality or both, or other serious adverse events. Well-designed randomised clinical trials are needed to determine the benefits and harms of HBIG versus placebo in prevention of MTCT of HBV.

Hepatitis B vaccine alone or with hepatitis B immunoglobulin in neonates of HBsAg+/HBeAg- mothers: a systematic review and meta-analysis

OBJECTIVES

The cost-effectiveness of augmenting immunization against hepatitis B infection with hepatitis B immunoglobulin (HBIG) remains controversial, particularly for the subpopulation of babies of HBsAg+/HBeAg- mothers that are considered as low-infective. We aimed to evaluate the effectiveness of vaccine alone compared with vaccine plus HBIG for the immunization of babies of HBsAg+/HBeAg- mothers.

METHODS

We searched PubMed, Scopus and Cochrane Central Register of Controlled Trials databases to identify studies comparing the effectiveness of combined immunization (vaccine plus HBIG) with vaccine alone in neonates of HBsAg+/HBeAg- mothers. A systematic review and meta-analysis of eligible studies was performed.

RESULTS

A total of nine eligible studies were identified (four randomized controlled trials). No difference was found regarding the primary outcome of our meta-analysis, namely occurrence of hepatitis B infection, between neonates who received vaccine only, compared with those who received both vaccine and HBIG (four studies, 3426 patients, OR=0.82, 95% CI=0.41-1.64). This finding was consistent with regards to seroprotection rate (four studies, 1323 patients, OR=1.24, 95% CI=0.97-1.58). Safety data were not reported in the included studies.

CONCLUSIONS

The available limited published evidence suggests that vaccine alone seems to be equally effective to the combination of HBIG and hepatitis B vaccine for neonates of HBsAg+/HBeAg- mothers in preventing infection. Further studies are needed in order to clarify the potential benefit of combined immunization to this specific subgroup of patients.

Seroprotection after recombinant hepatitis B vaccination among newborn infants: a review

INTRODUCTION

Hepatitis B vaccination starting at birth provides a safety net for infants exposed to hepatitis B virus (HBV) during delivery or in early life. Hepatitis B vaccine is recommended in the United States for infants prior to birthing facility discharge, and within the first 12h of life for infants born to hepatitis B surface antigen (HBsAg)-positive mothers. We performed a literature review and summarized the response to recombinant hepatitis B vaccine among infants.

METHODS

Studies published between 1987 and 2011 assessing seroprotection from recombinant hepatitis B vaccine starting within the first 30 days of life were eligible. Seroprotection was defined using an antibody to hepatitis B surface antigen (anti-HBs) threshold of 10mIU/mL at series completion. Infant seroprotection was compared in trial arms varying by maternal hepatitis B antigen status (e antigen [HBeAg], HBsAg), hepatitis B immune globulin (HBIG) administration, birth weight, vaccine dosage, schedule, and age at first dose.

RESULTS

Forty-three studies were included. The median seroprotection proportion overall was 98% (range 52%, 100%). The final median seroprotection proportions did not vary appreciably by maternal HBsAg status, HBIG administration, or schedule. Higher compared to lower dosage resulted in earlier increases in anti-HBs but not in final seroprotection proportions. Infants with birth weights <2000g compared to ≥2000g had lower median seroprotection proportions (93% and 98%, respectively). Median seroprotection proportions were also lower when infants with birth weights <2000g were vaccinated at 0-3 days of age compared to 1 month of age or older (68% versus 95%, respectively).

CONCLUSION

High levels of protection from recombinant hepatitis B vaccine are achieved in term infants vaccinated at birth, effectively preventing transmission of HBV and resultant morbidity and mortality. Implications, if any, for long-term protection are unknown for differences in responses among infants vaccinated at birth compared to ages older than 1 month.

Transplacentally acquired maternal antibody against hepatitis B surface antigen in infants and its influence on the response to hepatitis B vaccine

BACKGROUND

Passively acquired maternal antibodies in infants may inhibit active immune responses to vaccines. Whether maternal antibody against hepatitis B surface antigen (anti-HBs) in infants may influence the long-term immunogenicity of hepatitis B vaccine remains unknown.

METHODOLOGY/PRINCIPAL FINDINGS

Totally 338 pairs of mothers and children were enrolled. All infants were routinely vaccinated against hepatitis B based on 0-, 1- and 6-month schedule. We characterized the transplacental transfer of maternal anti-HBs, and compared anti-HBs response in children of mothers with or without anti-HBs. In a prospective observation, all 63 anti-HBs positive mothers transferred anti-HBs to their infants; 84.1% of the infants had higher anti-HBs concentrations than their mothers. One and half years after vaccination with three doses of hepatitis B vaccine, the positive rate and geometric mean concentration (GMC) of anti-HBs in 32 infants with maternal anti-HBs were comparable with those in 32 infants without maternal antibody (90.6% vs 87.5%, P = 0.688, and 74.5 vs 73.5 mIU/ml, P = 0.742, respectively). In a retrospective analysis, five and half years after vaccination with three doses vaccine, the positive rates of anti-HBs in 88 children of mothers with anti-HBs ≥1000 mIU/ml, 94 children of mothers with anti-HBs 10-999 mIU/ml, and 61 children of mothers with anti-HBs <10 mIU/ml were 72.7%, 69.2%, and 63.9% (P = 0.521), respectively; anti-HBs GMC in these three groups were 38.9, 43.9, and 31.7 mIU/ml (P = 0.726), respectively.

CONCLUSIONS/SIGNIFICANCE

The data demonstrate that maternal anti-HBs in infants, even at high concentrations, does not inhibit the long-term immunogenicity of hepatitis B vaccine. Thus, current hepatitis B vaccination schedule for infants will be still effective in the future when most infants are positive for maternal anti-HBs due to the massive vaccination against hepatitis B.

Serum ALT Levels as a Surrogate Marker for Serum HBV DNA Levels in HBeAg-negative Pregnant Women

In Stockholm, Sweden, the majority of pregnant women positive for hepatitis B surface antigen (HBsAg) are hepatitis Be antigen (HBeAg) negative. Newborns to HBeAg positive mothers receive vaccination and hepatitis B immunoglobulin (HBIg). Newborns to HBeAg negative mothers receive vaccine and HBIg only if the mothers have elevated ALT levels. The aim of this study was to retrospectively evaluate ALT levels as a surrogate marker for HBV DNA levels in HBeAg negative carrier mothers. Altogether 8947 pregnant women were screened for HBV markers from 1999 to 2001 at the Virology Department, Karolinska Hospital. Among mothers screened 192 tested positive for HBsAg (2.2%). 13 of these samples could not be retrieved. Of the remaining 179 sera, 8 (4%) tested positive for HBeAg and 171 (95.5%) were HBeAg negative. Among the HBeAg negative mothers, 9 had HBV DNA levels > 10(5) copies/ml, and of these 7 had normal ALT levels indicating low sensitivity of an elevated ALT level as a surrogate marker for high HBV DNA level. Furthermore, no correlation was found between ALT and HBV DNA levels. Hence, it is concluded that the use of ALT as a surrogate marker for high viral replication in HBeAg negative mothers could be questioned.

Influence of maternal antibody against hepatitis B surface antigen on active immune response to hepatitis B vaccine in infants

Transplacentally acquired maternal antibodies in infants may inhibit active immune responses to vaccines. In this study, we compared the immunogenicity of the recombinant hepatitis B vaccine, which was intramuscularly injected at 0, 1, and 6 months of age, in 71 infants born to mothers with positive or negative antibody against hepatitis B surface antigen (anti-HBs). Forty-one infants born to anti-HBs positive mothers were all positive at birth. At 2 months after the second injection, anti-HBs in 30 infants with negative maternal antibody was significantly higher than that in 41 infants with positive maternal anti-HBs (191.1mIU/ml vs. 96.2mIU/ml, P=0.018). At one month after the full immunization, the anti-HBs levels had no statistical difference between maternal anti-HBs negative and positive groups, but the antibody response in infants with high maternal anti-HBs (>1000mIU/ml) was significantly inhibited. Nevertheless, all infants had anti-HBs higher than the protective level. In conclusion, passively acquired maternal anti-HBs in infants may to some extent impair the antibody response to hepatitis B vaccine. The long-term efficacy of hepatitis B vaccine in infants with high titers of maternal anti-HBs remains to be further evaluated.

Hepatitis B immunisation for newborn infants of hepatitis B surface antigen-positive mothers

BACKGROUND

Hepatitis B vaccine and hepatitis B immunoglobulin are considered for newborn infants of HBsAg-positive mothers to prevent hepatitis B infection.

OBJECTIVES

To assess the beneficial and harmful effects of hepatitis B vaccines and hepatitis B immunoglobulin in newborn infants of HBsAg-positive mothers.

SEARCH STRATEGY

Trials were identified through The Cochrane Neonatal Group Controlled Trials Register, The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, and EMBASE (until February 2004), authors of trials, and pharmaceutical companies.

SELECTION CRITERIA

Randomised clinical trials comparing: plasma-derived vaccine (PDV) or recombinant vaccine (RV) versus no intervention, placebo, or other active vaccines; hepatitis B immunoglobulin versus no intervention, placebo, or other control immunoglobulin; as well as PDV or RV plus hepatitis B immunoglobulin versus no intervention, placebo, or other control vaccines or immunoglobulin.

DATA COLLECTION AND ANALYSIS

Outcomes are assessed at maximal follow-up. The primary outcome measure was hepatitis B occurrence, based on a blood specimen positive for HBsAg, HBeAg, or antibody to hepatitis B core antigen (anti-HBc). Binary outcomes are reported as relative risks (RR) with 95% confidence interval (CI). Subgroup analyses were performed with regard to methodological quality of the trial, mother's HBe-Ag status, and time of immunisation after birth.

MAIN RESULTS

We identified 29 randomised clinical trials, five of which were considered high quality. Only three trials reported inclusion of hepatitis B e-antigen negative mothers. Compared with placebo/no intervention, vaccine reduced hepatitis B occurrence (RR 0.28, 95% confidence interval (CI) 0.20 to 0.40, 4 trials). No significant differences of hepatitis B occurrence were found comparing recombinant vaccine (RV) versus plasma-derived vaccine (PDV) (RR 1.00, 95% CI 0.71 to 1.42, 4 trials) and high-dose versus low-dose vaccine (PDV: RR 0.97, 95% CI 0.55 to 1.68, 3 trials; RV: RR 0.78, 95% CI 0.31 to 1.94, 1 trial). Compared with placebo/no intervention, hepatitis B immunoglobulin or the combination of vaccine plus hepatitis B immunoglobulin reduced hepatitis B occurrence (hepatitis B immunoglobulin: RR 0.50, 95% CI 0.41 to 0.60, 1 trial; PDV plus hepatitis B immunoglobulin: RR 0.08, 95% CI 0.03 to 0.17, 3 trials). Compared with vaccine, vaccine plus hepatitis B immunoglobulin reduced hepatitis B occurrence (RR 0.54, 95% CI 0.41 to 0.73, 10 trials). Hepatitis B vaccine and hepatitis B immunoglobulin seem safe, but few trials reported on adverse events.

AUTHORS' CONCLUSIONS

Vaccine, hepatitis B immunoglobulin, and vaccine plus hepatitis B immunoglobulin prevent hepatitis B occurrence in newborn infants of HBsAg positive mothers.

Role of hepatitis B immunoglobulin in infants born to hepatitis B e antigen-negative carrier mothers in Taiwan

BACKGROUND

The efficacy of hepatitis B immunoglobulin (HBIG) in infants of hepatitis B e antigen (HBeAg)-negative hepatitis B surface antigen (HBsAg) carrier mothers in Taiwan is not clear.

OBJECTIVE

To describe the responses of infants born to HBeAg-negative carrier mothers receiving HBIG combined with hepatitis B vaccine.

METHODS

Term babies born to HBeAg-negative carrier mothers were assigned based on chart number to 1 of the 2 treatment groups. Group A infants (n = 94) received 0.5 ml (145 IU) of HBIG within 24 h of birth and 3 subsequent doses of recombinant hepatitis B virus (HBV) vaccine at 3 to 5 days, 1 month and 6 months of age. Group B infants (n = 122) received 3 doses of vaccines only. Infants (n = 19) born to HBeAg-positive carrier mothers were treated like those in Group A and are referred to as Group C. Sera obtained from infants at 2 and 7 months of age were tested for hepatitis B virus (HBV) markers.

RESULTS

There were 2 (1%; one in Group A and one in Group B) subclinical breakthrough hepatitis B infections among studied infants. One (5%) child of Group C had asymptomatic HBV infection at the age of 7 months and became a chronic carrier. The rate of protective anti-hepatitis B surface antibody (anti-HBs) titers achieved (>10 mIU/ml) by 2 months of age was significantly higher in Group A than that in Group B (98% vs. 57%, P < 0.001). However, it was not different by 7 months of age. Infants (Group A) immunized with HBIG and vaccine had a significantly higher geometric mean titer (GMT, milli-International Units/ml) of anti-HBs than those (Group B) with vaccines only at 2 months of age (P < 0.001). Conversely at 7 months of age, the GMT of anti-HBs was significantly higher in infants who received vaccine only (P = 0.001).

CONCLUSIONS

A protective level of antibodies was achieved earlier in those infants receiving both passive and active immunizations. However, infants receiving active immunizations alone achieved a higher GMT at 7 months of age. There was no clear benefit of passive-active vs.active immunization alone for chronic HBV infection in infants of HBsAg-positive, HBeAg-negative mothers.

An appraisal of the efficacy and cost effectiveness of antenatal screening for hepatitis B

In this review published data are used to determine the benefits and costs of antenatal screening for hepatitis B carriers to prevent the later occurrence of hepatoma and chronic liver disease in their offspring. In Britain, babies born to carrier mothers have a 25% risk of perinatal infection and of becoming carriers themselves (the risk is 82% if their mothers are positive for the e antigen and 10% if negative). The carrier state increases the risk of hepatoma an estimated 86 times and the risk of chronic liver disease 20 times. Life table analysis showed that there is an 11% lifetime risk in carriers in Britain of dying from hepatoma (which results in seven years of life lost on average) and a 7% risk of chronic liver disease (14 years of life lost). Neonatal vaccination reduces the risk of the infant becoming a carrier by about 90%. Perinatal transmission occurs in 38 of every 100,000 neonates in Britain. Antenatal screening of all women and vaccinating babies of carrier mothers would prevent perinatal transmission in 34 of the 38 children (90%), or 255 per year in Britain. Of these 34, 8.4 children would be Chinese in ethnic origin, 4.2 African, 11.5 South Asian (from the Indian subcontinent), 2.0 Caribbean, and 7.3 would be white. Six deaths in the 34 from hepatoma or chronic liver disease caused by hepatitis B would then be prevented. The direct cost in Britain of screening all women, irrespective of ethnicity, at their first pregnancy only, would be 1300 pounds for each year of life saved (undiscounted) or 2500 pounds if screening at every pregnancy. Screening just Chinese, Africans, and South Asians, at first pregnancy only, would cost 330 pounds for each year of life saved but would prevent only 64% of these deaths. Vaccinating the infants of carrier mothers is likely also to prevent horizontal transmission of hepatitis B in early childhood and prevent the carrier state developing in an estimated three extra children for each child protected from vertical transmission. When this is taken into account the number of deaths prevented increases fourfold, reducing the cost for each year of life saved by 75%. Screening all women at first pregnancy only is an acceptably cost effective policy in Britain (1300 pounds for each year of life saved), actually preventing 45 deaths a year from hepatoma and chronic liver disease (or about 180 deaths if those horizontally infected are included), at a total cost of 540,000 pounds a year. It has the advantage of being comprehensive, equitable, and easier to implement than a policy based on screening of high risk ethnic groups.

Prevention of hepatitis B by immunization of the newborn infant--a long-term follow-up study in Stockholm, Sweden

In order to assess the present hepatitis B immunization program in Stockholm, Sweden, 212 children of HBsAg carrier mothers were followed up 2-9 years after birth. In babies of HBeAg-positive mothers a combined passive and active immunization schedule with hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine was used. Among 25 children to such mothers, 1 HBsAg carrier and 5 children with asymptomatic seroconversion were found. To newborns of HBeAg-negative/anti-HBe-negative mothers, only vaccine was given. Among 15 such children, no HBsAg carrier (but 1 child with an asymptomatic seroconversion) was found. In babies of HBeAg-negative/anti-HBe-positive mothers, immunization was withheld between 1983 and 1987. Among 90 such children, 1 HBsAg carrier and 8 asymptomatic seroconversions were detected. After 1987, newborns in this group were vaccinated whereafter 3 asymptomatic seroconversions were found among 82 children. We conclude that in low prevalence areas a screening program for HBsAg should be offered to pregnant women originating from hepatitis B endemic regions, since immunoprophylaxis gave long-term protection to most children at risk. Children born to HBeAg-positive mothers should receive vaccine in combination with HBIg, whereas for children of mothers lacking HBeAg, vaccination only seems sufficient, at least if a rapid vaccination schedule is used.

Familial clustering of hepatitis B virus infections and prevention of perinatal transmission by immunization with a reduced number of doses in an area of intermediate endemicity (Tunisia)

Hepatitis B surface antigen (HBsAg) was detected in 3.3% of 7162 pregnant Tunisian women tested and HBeAg in 9.6% of the HBsAg-positive mothers. Family members of 46 of these HBsAg-positive mothers (33 husbands and 61 children aged 1-6 years) were investigated for the presence of HBV markers. HBsAg was detected in 21% of the children and 18% of the husbands. Fifty children born to HBsAg-positive mothers received hepatitis B vaccine at birth, at the age of 2-3 months and at the age of 9 months. After immunization, anti-HBs were detected in 92% of them with an anti-HBs geometric mean titre of 415 mIU ml-1. Compared with the HBsAg carrier state in older siblings, the protective efficacy was estimated to be 60%. It was 100% for infants born to HBeAg-negative mothers, but only 31% for those born to HBeAg-positive mothers. For a better efficacy, the schedule of the EPI needs to be modified to include an immunization session at 1 month of age.

Evaluation of prophylaxis against hepatitis B in a large municipal hospital

BACKGROUND

Perinatal transmission of hepatitis B can be interrupted by the administration of hepatitis B vaccine and hepatitis B globulin to the infants of carrier mothers. Universal screening of pregnant women makes this strategy possible.

METHODS

To evaluate the implementation of universal hepatitis B surface antigen screening of women giving birth at Kings County Hospital Center during 1988, we reviewed laboratory records to find all women with a positive test result who might give birth. We also randomly reviewed records of women who gave birth to live infants to determine the percentage of screening in the population. Infants' charts were reviewed for documentation of maternal hepatitis B surface antigen status and administration of hepatitis B immune globulin and vaccine.

RESULTS

Sixty infants who lived long enough to receive antihepatitis B prophylaxis were distinguished out of a total of 5146 births. Screening was done for from 66.8% to 80.4% (95% confidence interval) of the mothers of these infants. Although 44 of 60 infants received hepatitis B immune globulin and 39 of 60 infants received vaccine, only 27 of 60 received vaccine within 12 hours in combination with immune globulin (Centers for Disease Control-recommended therapy).

CONCLUSIONS

Documentation of hepatitis B surface antigen in the infant's delivery room record was present in 23 of 60 infants. Those infants all received hepatitis B immune globulin and vaccine; 21 received hepatitis B immune globulin within 12 hours. Hepatitis B immune globulin was given within 12 hours to 8 of 37 infants who lacked documentation of hepatitis B surface antigen status on the delivery room record. These differences were highly significant (p less than 0.001) even when only the 40 patients who had documented prenatal screening at Kings County Hospital Center (21/23 vs 4/17). Prenatal care did not have any effect on outcome.

Combined immunoprophylaxis in the prevention of perinatal transmission of hepatitis B and hepatitis D virus infections in Saudi children

The efficacy of the combined immunoprophylaxis approach (passive plus active immunization) was evaluated in babies born to 52 HBsAg-carrier Saudi mothers, of whom seven (13.5%) were HBeAg-positive and seven were anti-HDV-positive. Newborns were given 100 IU of hepatitis B immune globulin (HBIG) from the Hepuman Berna-Swiss Serum and Vaccine Institute, Berne, and hepatitis B vaccine (5 micrograms) within 12 hours of birth, and the vaccine was given again at 1 and 6 months of age (5 micrograms/injection). After 18 months of follow-up, all but one baby had protective levels of antibody to HBsAg and none of the babies born to anti-HDV-positive carrier mothers showed evidence of HDV infection. These results show that the combined immunoprophylaxis approach is quite successful in protecting against perinatal transmission of HBV and HDV in the Saudi population. Furthermore, early vaccination against HBV will also protect against HDV infection later in life.

Perinatal transmission of hepatitis B virus in high-incidence countries

Hepatitis B is a serious public health problem throughout the world. Hepatitis B virus (HBV) induces acute hepatitis with a case-fatality rate of about 1%. Even more important, 5-10% of patients infected with HBV become chronic carries and about 25% of these will die due to cirrhosis and hepatocellular carcinoma. The reservoir of HBV chronic carriers in the world is estimated at more than 200 million people and 80% of them reside in Asia and the western Pacific. In high-incidence areas, such as south-east Asia, perinatal transmission of HBV from carrier mothers to newborns appears to be the most important factor for the high prevalence of HBV infection and 70-90% of infants born to HBsAg/HBeAg-positive mothers become chronic carriers. Three possibilities of transmission of HBV from carrier mothers to newborns are suggested: (a) transplacental transmission in utero - it was estimated that such transmission occurred in 5-15% of newborns; (b) transmission during delivery, which is considered the main mode of perinatal transmission; (c) postnatal transmission from mother to newborn, which is not common. HBeAg is the main maternal factor in determining whether infection of newborns will occur; the expression of this antigen seems to be determined genetically. Recently it has shown that immunoprophylaxis is highly effective in preventing the development of the carrier state in infants born to HBsAg/HBeAg-positive mothers. Only 5-10% of high-risk infants are not protected by vaccination. If it becomes possible to immunize the entire world population including all babies born to carrier mothers at birth, and if our knowledge of the mechanisms of perinatal transmission of HBV is accurate, the carriers and acute cases of HB ought to disappear in two to three generations.