Protective effect of hepatitis B vaccine combined with two-dose hepatitis B immunoglobulin on infants born to HBsAg-positive mothers

Impact of timing on protection of combined immunoprophylaxis in preventing mother-to-child transmission of hepatitis B virus: a retrospective study

Objective: To evaluate the impact of timing combined immunoprophylaxis on mother-to-child transmission (MTCT) of the hepatitis B virus (HBV) in pregnant women living with hepatitis B. Methods: A retrospective cohort study was included HBsAg-positive pregnant women who delivered full-term at Tianjin Third Central Hospital from January 2019 to December 2021. The objective of this study is to determine whether early administration of hepatitis B immune globulin (HBIG) and the first dose of hepatitis B vaccination after birth can further improve protection. Result: A total of 694 pregnant women living with hepatitis B were included; 93 infants from these mothers were lost to follow-up [including moving (n = 21), emigrating (n = 26), changing contact information (n = 27), and other reasons (n = 19)], leaving 601 infants for analysis. The incidence in babies born to mothers with hepatitis B was 1.50% (9/601). Based on the different timing of combined immunoprophylaxis administration after birth, 601 infants were divided into two groups (within 2 h and within 2-12 h). The incidence in babies born to mothers with hepatitis B were 0.32% (1/308) and 2.73% (8/293) for infants who received combined immunoprophylaxis within 2 h and between 2 and 12 h of birth, respectively (p = 0.037). The infection incidence of infants born to HBeAg-positive mothers and HBeAg-positive mothers who did not receive antiviral treatment during pregnancy was lower in the 2-h group compared to the 2-12 h group (0.72% vs. 5.84%, p = 0.04 and 1.20% vs. 9.46%, p = 0.047). Conclusion: Using combined immunoprophylaxis as soon as possible (within two hours of birth) may protect against MTCT of HBV more.

The effects of increased dose of hepatitis B vaccine on mother-to-child transmission and immune response for infants born to mothers with chronic hepatitis B infection: a prospective, multicenter, large-sample cohort study

BACKGROUND

Appropriate passive-active immunoprophylaxis effectively reduces mother-to-child transmission (MTCT) of hepatitis B virus (HBV), but the immunoprophylaxis failure was still more than 5% under the current strategy. The study objective was to investigate the effects of high dose of HB vaccine on MTCT and immune response for infants born to hepatitis B surface antigen (HBsAg)-positive mothers.

METHODS

This was a prospective, multicenter, large-sample cohort study in four sites of China, and 955 pairs of HBsAg-positive mothers and their infants were enrolled in our investigation. The infants were given 10 μg or 20 μg HB vaccine (at age 0, 1, and 6 months) plus HB immunoglobulin (at age 0 and 1 month). Serum HBsAg, antibody to HBsAg (anti-HBs), and/or HBV DNA levels in the infants were determined at age 12 months. The safety of 20 μg HB vaccine was evaluated by adverse events and observing the growth indexes of infants.

RESULTS

Thirteen of 955 infants were HBsAg-positive at 12 months. Stratification analysis showed that immunoprophylaxis failure rates in the 20 μg group were not significantly different from the 10 μg group, whatever maternal HBV load was high or not. But the high dose of HB vaccine significantly reduced low-response rate (anti-HBs 10-100 IU/L) (P = 0.002) and middle-response rate (anti-HBs 100-1000 IU/L) (P = 0.022) and improved high-response rate (anti-HBs ≥ 1000 IU/L) (P < 0.0001) in infants born to mothers with HBV DNA < 5 log₁₀ IU/mL. For infants born to mothers with HBV DNA ≥ 5 log₁₀ IU/mL, 20 μg HB vaccine did not present these above response advantages. The 20 μg HB vaccine showed good safety for infants.

CONCLUSIONS

The 20 μg HB vaccine did not further reduce immunoprophylaxis failure of infants from HBsAg-positive mothers, but increased the high-response and decreased low-response rates for infants born to mothers with HBV DNA < 5 log₁₀ IU/mL.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR-PRC-09000459.

Risk factors related to postpartum hepatic inflammation in pregnant women with chronic hepatitis B

OBJECTIVES

To investigate liver function after pregnancy in women with chronic hepatitis B virus (HBV) and factors related to postpartum abnormalities.

METHODS

A total of 317 pregnant women were included in this study and 138 had an HBV DNA level. In this trial, the highest number and proportion of hepatitis B surface antigen-positive mothers with postpartum hepatic inflammation were at 1 month after delivery.

RESULTS

Baseline liver function of postpartum women with hepatic inflammation was significantly higher than that in those before delivery. The rates of hepatitis B e-antigen (HBeAg)-positive status, baseline HBV DNA levels, gestational diabetes mellitus, and antiviral therapy during pregnancy were significantly higher in the hepatic inflammation group than in the control group. Among the 138 women who received antiviral therapy, 83 withdrew from antiviral therapy immediately after delivery and 55 continued antiviral therapy for at least 1 month after delivery. Multivariate logistic regression analysis showed that HBeAg-positivity and gestational diabetes mellitus were associated with hepatic inflammation after delivery. Postpartum hepatic inflammation occurred mostly at 1 month after delivery in pregnant women with HBV infection.

CONCLUSIONS

Close monitoring of women with HBV during pregnancy is required, especially for those who are HBeAg-positive and have gestational diabetes mellitus.

Accuracy of HBeAg to identify pregnant women at risk of transmitting hepatitis B virus to their neonates: a systematic review and meta-analysis

BACKGROUND

Prevention of mother-to-child transmission (MTCT) of hepatitis B virus (HBV) involves neonatal immunoprophylaxis, with a birth dose of hepatitis B vaccine and immune globulin, and provision of peripartum antiviral prophylaxis in highly viraemic women. However, access to assays to quantify HBV DNA levels remains inadequate in resource-poor settings. This study was commissioned by WHO and aimed to identify the HBV DNA threshold for MTCT, to assess the sensitivity and specificity of hepatitis B e antigen (HBeAg) testing to identify pregnant women with HBV DNA levels above this threshold, and to predict MTCT of HBV infection on the basis of HBeAg testing.

METHODS

For this systematic review and meta-analysis, we searched the PubMed, EMBASE, Scopus, CENTRAL, CNKI, and Wanfang databases for studies of pregnant women with chronic HBV infection without concurrent antiviral therapy, published between Jan 1, 2000, and April 3, 2019. Studies were eligible for inclusion if MTCT in mother-child pairs could be stratified by different levels of maternal HBV DNA during pregnancy, if maternal HBeAg status could be stratified by HBV DNA level, and if the MTCT status of infants could be stratified by maternal HBeAg status during pregnancy. Studies that selected pregnant women on the basis of HBeAg serostatus or HBV DNA levels were excluded. Aggregate data were extracted from eligible studies by use of a pre-piloted form; study authors were contacted to clarify any uncertainties about potential duplication or if crucial information was missing. To pool sensitivities and specificities of maternal HBeAg to identify highly viraemic women and to predict MTCT events, we used the DerSimonian-Laird bivariate random effects model. This study is registered with PROSPERO, CRD42019138227.

FINDINGS

Of 9007 articles identified, 67 articles (comprising 66 studies) met the inclusion criteria. The risk of MTCT despite infant immunoprophylaxis was negligible (0·04%, 95% CI 0·00-0·25) below a maternal HBV DNA level of 5·30 log₁₀ IU/mL (200 000 IU/mL) and increased above this threshold. The pooled sensitivity of HBeAg testing to identify HBV DNA levels of 5·30 log₁₀ IU/mL or greater in pregnant women was 88·2% (83·9-91·5) and pooled specificity was 92·6% (90·0-94·5). The pooled sensitivity of HBeAg testing in predicting MTCT of HBV infection despite infant immunoprophylaxis was 99·5% (95% CI 91·7-100) and pooled specificity was 62·2% (55·2-68·7).

INTERPRETATION

Maternal HBV DNA of 5·30 log₁₀ IU/mL or greater appears to be the optimal threshold for MTCT of HBV infection despite infant immunoprophylaxis. HBeAg is accurate to identify women with HBV DNA levels above this threshold and has high sensitivity to predict cases of immunoprophylaxis failure. In areas where HBV DNA assays are unavailable, HBeAg can be used as an alternative to assess eligibility for antiviral prophylaxis.

FUNDING

World Health Organization.

Increased protection of earlier use of immunoprophylaxis in preventing perinatal transmission of hepatitis B virus

BACKGROUND

Passive-active immunoprophylaxis against mother-to-child transmission (MTCT) of hepatitis B virus (HBV) recommends administer hepatitis B immunoglobulin (HBIG) and birth dose hepatitis B vaccine in infants within 12 or 24 hours after birth. With this protocol, MTCT of HBV still occurs in 5-10% infants of HBV-infected mothers with positive hepatitis B e antigen (HBeAg).

METHODS

The present study aimed to investigate whether earlier administration of HBIG and hepatitis B vaccine after birth can further increase the protection efficacy.

RESULTS

Totally, 1140 HBV-infected pregnant women were enrolled, and 982 infants (9 twins) of 973 mothers were finally followed up at 9.6 ± 1.9 months age. HBIG and birth dose vaccine were administered in newborn infants with a median 0.17 hour (0.02-1.0) after birth. The overall rate of MTCT was 0.9% (9/982), with none (0%) of 607 infants of HBeAg-negative mothers and 9 (2.4%) of 375 infants of HBeAg-positive mothers. All nine HBV-infected infants were born to mothers with HBV DNA >2.75×106 IU/ml. Maternal HBV DNA levels >1×106 IU/ml was an independent risk factor (OR = 10.627, 95% CI: 2.135-+∞) for immunoprophylaxis failure.

CONSLUSIONS

Earlier use (within one hour after birth) of HBIG and hepatitis B vaccine can provide better protection efficacy against MTCT of HBV.

Is the function of the HBeAg really unknown?

The immune response to the hepatitis B virus (HBV) vaccine in newborns of hepatitis B e antigen (HBeAg)-positive or HBeAg-negative mothers is the subject of Huang et al. The authors report no correlation between the HBeAg status of the mothers/cord blood and the newborns immune response to the vaccine, but, unfortunately, draw unfounded conclusions regarding the tolerogenic potential of in utero exposure to HBeAg. In this reply, I address the possible influence of in utero exposure to the HBeAg, and briefly review other characteristics of the HBeAg, that may promote HBV chronicity. I argue that the function of HBeAg should no longer be considered "unknown" and that immunotolerance/immunomodulation represent the dominant functions of the HBeAg in viral-host interactions.

Comparison of antibody response to hepatitis B vaccination in infants with positive or negative maternal hepatitis B e antigen (HBeAg) in cord blood: implication for the role of HBeAg as an immunotolerogen

Hepatitis B e antigen (HBeAg) has been considered to cause immunotolerance to hepatitis B virus (HBV) in newborn infants after fetal HBeAg exposure. This study compared anti-HBs responses to hepatitis B vaccination in infants who were born to HBeAg-positive and -negative mothers respectively, to investigate whether fetal HBeAg exposure may induce immunotolerance to HBV. Totally 265 infants who received recommended neonatal immunoprophylaxis against hepatitis B and had no HBV infection were included. Anti-HBs levels were compared between 124 infants with cord blood positive HBeAg and 141 infants with cord blood negative HBeAg at 7-12 months of age. The infants in two groups had similar age at the follow-up (10.0 ± 2.3 vs 10.1 ± 2.3 months, P = 0.590). Overall, 259 (97.7%) of 265 infants achieved anti-HBs levels (mIU/ml) ≥10 and 6 (2.3%) others had anti-HBs <10. Of 124 HBeAg-positive infants at birth, 46.0%, 39.5%, 12.1%, and 2.4% had anti-HBs levels (mIU/ml) ≥1000, 100-999.9, 10-99.9, and <10, respectively. Of 141 HBeAg-negative infants at birth, 35.5%, 48.9%, 13.5%, and 2.1% showed ≥1000, 100-999.9, 10-99.9, and <10, respectively. The proportions of each anti-HBs level between the two groups were comparable (all P > 0.05). Additionally, the distribution of anti-HBs response levels were also comparable in infants with high and low HBeAg levels (P = 0.818). In conclusions, the fetal HBeAg exposure does not inhibit the antibody response to neonatal hepatitis B vaccination. The data suggest that HBeAg appears not inducing immunotolerance to HBV.

The management of hepatitis B and hepatitis C in children

In the present paper, we review the increased disease burden of hepatitis B (HBV) and hepatitis C (HCV) infection that is recognized worldwide; especially in children when the most common mode of transmission is vertically from infected mothers. In children with HBV and HCV infection, spontaneous clearance of the virus in the first years of life is not common, in contrast with adults, but these patients often stay asymptomatic until early adulthood, when disease has progressed to chronic hepatitis with increased risk of cirrhosis and its complication, and hepatocellular carcinoma. Due to limited treatment options of HBV infection in the pediatric population, clinicians focus on primary prevention, by vaccinating all infants during their first days of life. Infants born to infected mothers, receive intravenous immunoglobulin on top of the vaccine, and thus preventing transmission in 95% of the infants. While for HCV infection, since there is no vaccine to prevent HCV disease, providers focus primarily on treatment. The treatment landscape of HCV infection in children rapidly evolves, away from interferon regimens, and towards direct-acting antiviral agents that have a safer and more efficacious drug profile. Currently, there are ongoing clinical trials investigating the efficacy and tolerance of direct-acting agents in children below 12 years of age.

Safety and efficacy of telbivudine in late pregnancy to prevent mother-to-child transmission of hepatitis B virus: A multicenter prospective cohort study

Infection of hepatitis B virus (HBV) occurs in ~10% of infants of HBV-infected mothers with positive hepatitis B e antigen (HBeAg) after immunoprophylaxis. We aimed to evaluate the safety and efficacy of telbivudine used during late pregnancy for preventing mother-to-child transmission of HBV. We conducted a multicenter prospective cohort study in 5 hospitals from 2012 to 2014, which enrolled HBV-infected singleton pregnant women with positive HBeAg. By their choice, women were divided into therapy (telbivudine 600 mg/day, from gestation 28-32 weeks to 3-4 weeks postpartum) and control (no antiviral agent) groups. Infants received passive-active immunoprophylaxis and follow-up at the age of 7-14 months. Totally, 328 pregnant women were included: 149 in the telbivudine group and 179 in the control group. Baseline HBV DNA levels were similar in the 2 groups (7.43 vs 7.37 log₁₀ IU/mL, P = .711). At delivery, HBV DNA levels in the telbivudine and control groups were 3.80 and 7.26 log₁₀ IU/mL, respectively (P < .0001). Of the infants, 128 (85.9%) in the telbivudine group and 156 (87.2%) in the control group were followed up. No infant in the telbivudine group had chronic infection, while 2 (1.28%) infants in the control group did (P = .503). Three (2.34%) infants in the telbivudine group, but none in the control group, had severe congenital or developmental abnormalities (P = .090). The data indicate that telbivudine may block perinatal HBV transmission. However, larger studies are required to clarify whether anti-HBV therapy in pregnancy is associated with severe adverse effects in the foetuses and infants.

Prevention of Chronic Hepatitis B after 3 Decades of Escalating Vaccination Policy, China

China’s hepatitis B virus (HBV) prevention policy has been evaluated through nationally representative serologic surveys conducted in 1992 and 2006. We report results of a 2014 serologic survey and reanalysis of the 1992 and 2006 surveys in the context of program policy. The 2014 survey used a 2-stage sample strategy in which townships were selected from 160 longstanding, nationally representative, county-level disease surveillance points, and persons 1–29 years of age were invited to participate. The 2014 sample size was 31,713; the response rate was 83.3%. Compared with the 1992 pre–recombinant vaccine survey, HBV surface antigen prevalence declined 46% by 2006 and by 52% by 2014. Among children <5 years of age, the decline was 97%. China’s HBV prevention program, targeted toward interrupting perinatal transmission, has been highly successful and increasingly effective. However, this progress must be sustained for decades to come, and elimination of HBV transmission will require augmented strategies.

No response to hepatitis B vaccine in infants born to HBsAg(+) mothers is associated to the transplacental transfer of HBsAg

BACKGROUND

No or low hepatitis B (HB) vaccine response is more frequent in infants from HBsAg(+) mothers than those from HBsAg(-). Our previous study found temporary positivity of HBsAg in infants from HBsAg(+) mothers. In this study, we hypothesized that HBsAg in infant blunt immune response to standard hepatitis B vaccination.

METHODS

A total of 328 consecutive HBsAg(+) mothers and their offspring were enrolled. Blood samples were taken from mothers and their infants and quantified for HBsAg, anti-HBs titer and HBV DNA load concentration; Placenta samples were collected to stain for HBsAg.

RESULTS

First, 6.7% infants (22/328) showed anti-HBs titer lower than 10 mIU/mL after HB vaccination (non-response to HB vaccine). HBsAg(+) newborns showed higher risk of non-response than HBsAg(-) infants (13.0% versus 5.0%, p = 0.016). Infants from high HBsAg titer mothers displayed higher risk of HBsAg positivity at birth than those from low titer mothers (45.3% versus 2.8%, p < 0.001). HBsAg titer in mothers of HBsAg(+) newborns was much higher than mothers of HBsAg(-) newborns (p < 0.001). All those data supported HBsAg can be transferred through placenta. Our hypothesis was further reinforced by immunostaining with specific antibody against HBsAg, a substantial higher prevalence (87.5% versus 30.8%, p = 0.024) and stronger immunostaining (p = 0.008) was demonstrated in HBsAg(+) group comparing with placenta of the HBsAg(-) group.

CONCLUSION

No response to HB vaccine in infants of HBsAg(+) mothers was associated to the transplacental transfer of HBsAg.

Protective effect of an improved immunization practice of mother-to-infant transmission of hepatitis B virus and risk factors associated with immunoprophylaxis failure

Although routine immunoprophylaxis has been known to reduce hepatitis B virus (HBV) transmission, immunoprophylaxis failure still occurs. The study aimed to investigate the protective efficacy of an improved immunoprophylaxis protocol to prevent mother-to-infant transmission of HBV and to explore the potential risk factors associated with immunoprophylaxis failure and low antibody response.A prospective observational cohort study was conducted from July 2012 to April 2015. A total of 863 HBsAg-positive mothers and their 871 infants (8 pairs of twins) were included in the study. Two different hepatitis B vaccine doses (20 or 10 μg) were administered to the infants based on the hepatitis B e-antigen (HBeAg) status of their mothers. Simultaneously, hepatitis B immunoglobulin (HBIG) was administered to the infants. Initial injections of HBIG and the hepatitis vaccine were given within 2 hours after birth. Rates of HBV infections among the infants were evaluated at 7 months of age. Factors associated with immunoprophylaxis failure and low responses to vaccination were analyzed by unconditional logistic regression..At 7 months of age, no immunoprophylaxis failure was observed in the 565 infants born to HBeAg-negative mothers. Among the 306 infants born to HBeAg-positive mothers, immunoprophylaxis failed in 16 infants (5.2%) of the infants and they were found to be HBsAg-positive. Further analysis showed that HBV DNA levels ≥10 IU/mL [odds ratio (OR) = 4.53, 95% confidence interval (95% CI): 1.19-17.34], delayed vaccination (OR = 4.14, 95% CI: 1.00-17.18), and inadequate initial injections (OR = 7.69, 95% CI: 1.71-34.59) were independently associated with immunoprophylaxis failure. Adequate titers of antibody to HBsAg (anti-HBs, ≥100 mIU/mL) were present in 96.5% of immunoprophylaxis-successful infants. For full-term infants, birth weights <3000 g were correlated with low immune responses to vaccination.This improved immunoprophylaxis protocol is effective in preventing perinatal transmission of HBV. Among infants with HBeAg-positive mothers, high HBV viral loads and inadequate and delayed initial injections were associated with immunoprophylaxis failure. The majority of the infants in our study produced adequate levels of protective anti-HBs titers after immunoprophylaxis. Additional efforts to further reduce perinatal transmission should be considered, especially for HBeAg-positive mothers.

Prophylaxis of vertical HBV infection

INTRODUCTION

An appropriate management of HBV infection is the best strategy to finally reduce the total burden of HBV infection. Mother-to-child transmission (MTCT) is responsible for more than one third of chronic HBV infections worldwide. Because HBV infection in infancy or early childhood often leads to chronic infection, appropriate prophylaxis and management of HBV in pregnancy is crucial to prevent MTCT.

AREAS COVERED

The prevention of HBV vertical transmission is a complex task and includes: universal HBV screening of pregnant women, administration of antivirals in the third trimester of pregnancy in women with high viral load and passive-active HBV immunoprophylaxis with hepatitis B vaccine and hepatitis B immune globulin in newborns of all HBV infected women.

EXPERT OPINION

Universal screening of pregnant women for HBV infection, early identification of HBV DNA level in HBV-infected mothers, maternal treatment with class B according to FDA antivirals and passive/active anti-HBV immunoprophylaxis to newborns of HBV-positive mothers are crucial strategies for reducing vertical HBV transmission rates. Consideration of caesarean section in order to reduce the risk of vertical HBV transmission should be recommend in HBV infected pregnant women with high viral load despite antiviral therapy or when the therapy in the third trimester of pregnancy is not available.

Prevention of perinatal hepatitis B transmission in Haimen City, China: Results of a community public health initiative

In regions where hepatitis B virus (HBV) is endemic, perinatal transmission is common. Infected newborns have a 90% chance of developing chronic HBV infection, and 1 in 4 will die prematurely from HBV-related liver disease. In 2010, the Hepatitis B Foundation and the Haimen City CDC launched the Gateway to Care campaign in Haimen City, China to improve awareness, prevention, and control of HBV infection citywide. The campaign included efforts to prevent perinatal HBV transmission by screening all pregnant women for hepatitis B surface antigen (HBsAg), following those who tested positive, and administering immunoprophylaxis to their newborns at birth. Of 5407 pregnant women screened, 185 were confirmed HBsAg-positive and followed until delivery. At age one, 175 babies were available for follow up testing. Of those, 137 tested negative for HBsAg and positive for antibodies to HBsAg, indicating protection. An additional 34 HBsAg-negative babies also tested negative for antibodies to HBsAg or had indeterminate test results, were considered to have had inadequate immune responses to the vaccine, and were given a booster dose. A higher prevalence of nonresponse to HBV vaccine was observed among babies born to hepatitis B e antigen (HBeAg)-positive mothers and mothers with high HBV DNA titers. The remaining 4 babies tested positive for HBsAg and negative for antibodies, indicative of active HBV infection. The mothers of all 4 had viral loads ≥8×10(6) copies/ml in the third trimester. Although inadequate response or nonresponse to HBV vaccine was more common among babies born to HBeAg-positive and/or high viral load mothers, these risk factors did not completely predict nonresponsiveness. All babies born to HBV-infected mothers should be tested upon completion of the vaccine series to ascertain adequate protection. Some babies of HBeAg-positive mothers with high viral load may still become HBV infected despite timely immunoprophylaxis with HBV vaccine and HBIG.

Epidemiology of Hepatitis B Virus Infection in China: Current Status and Challenges

The prevalence of hepatitis B is high in China. Based on the National Disease Supervision Information Management System of China, the mean reported incidence of hepatitis B was 84.3 per 100,000 in China between 2005 and 2010. There are differences in population distribution based on region and ethnic group. Here, risk factors, virological characteristics, and prophylaxis of hepatitis B in China are reviewed. Although the prevalence of HBV infection is gradually declining, there are many challenges in HBV infection control, including higher prevalence in floating population, poor compliance of antiviral therapy, and high disease burden.

Predictors of Poor Response After Primary Immunization of Hepatitis B Vaccines for Infants and Antibody Seroprotection of Booster in a Metropolis of China

To evaluate proportion and predictors of poor response in infants and appraise booster seroprotection, we surveyed 2047 infants in Shanghai and detected antibody to hepatitis B (HB) surface antigen (anti-HBs). Poor responders were randomized into 2 groups, given booster with 5 µg and 10 µg hepatitis B vaccine (HepB), respectively. Proportion of infants with titer <10 mIU/mL and 10 to 99 mIU/mL was 1.86% and 15.14%, respectively. Multivariate logistic regression suggested infants of male, aged 13 to 18 months, premature, administered with 5 µg HepB or mother positive for HB surface antigen (HBsAg) and HBe antigen (HBeAg) would more likely develop worse response. Difference of geometric mean concentration between the first and full booster was not statistically significant both for 5 µg and for 10 µg HepB groups. The seroprotective rate were higher for infants with 10 µg HepB than those with 5 µg HepB ( P > .05). Therefore, it is concluded that booster for poor vaccinees with 10 µg HepB could achieve satisfactory seroprotection.

Analysis of residual perinatal transmission of hepatitis B virus (HBV) and of genetic variants in human immunodeficiency virus and HBV co-infected women and their offspring

BACKGROUND

Despite implementation of universal infant hepatitis B (HB) vaccination, mother-to-child transmission (MTCT) of hepatitis B virus (HBV) still occurs. Limited data are available on the residual MTCT of HBV in human immunodeficiency virus (HIV)-HBV co-infected women.

OBJECTIVES

We assessed the prevalence of HBV infection among HIV-infected pregnant women and the rate of residual MTCT of HBV from HIV-HBV co-infected women and analyzed the viral determinants in mothers and their HBV-infected children.

STUDY DESIGN

HIV-1 infected pregnant women enrolled in two nationwide perinatal HIV prevention trials in Thailand were screened for HB surface antigen (HBsAg) and tested for HBeAg and HBV DNA load. Infants born to HBsAg-positive women had HBsAg and HBV DNA tested at 4-6 months. HBV diversity within each HBV-infected mother-infant pair was analyzed by direct sequencing of amplified HBsAg-encoding gene and cloning of amplified products.

RESULTS

Among 3312 HIV-1 infected pregnant women, 245 (7.4%) were HBsAg-positive, of whom 125 were HBeAg-positive. Of 230 evaluable infants born to HBsAg-positive women, 11 (4.8%) were found HBsAg and HBV DNA positive at 4-6 months; 8 were born to HBeAg-positive mothers. HBV genetic analysis was performed in 9 mother-infant pairs and showed that 5 infants were infected with maternal HBV variants harboring mutations within the HBsAg "a" determinant, and four were infected with wild-type HBV present in highly viremic mothers.

CONCLUSIONS

HBV-MTCT still occurs when women have high HBV DNA load and/or are infected with HBV variants. Additional interventions targeting highly viremic women are thus needed to reduce further HBV-MTCT.

Breastfeeding is not a risk factor for mother-to-child transmission of hepatitis B virus

Background

Many clinicians do not encourage breastfeeding in hepatitis B virus (HBV) carriers, since HBV DNA can be detected in breast milk and breast lesions may increase exposure of infants to HBV. The aim of this study was to determine whether breastfeeding may add risk for perinatal HBV transmission.

Methodology/Principal Findings

Totally 546 children (1–7-year-old) of 544 HBV-infected mothers were investigated, with 397 breastfed and 149 formula-fed; 137 were born to HBeAg-positive mothers. All children had been vaccinated against hepatitis B but only 53.3% received hepatitis B immune globulin (HBIG). The overall prevalence of HBsAg+, HBsAg−/anti-HBc+, and anti-HBs (≥10 mIU/ml) in children was 2.4%, 3.1%, and 71.6% respectively. The HBsAg prevalence in breast- and formula-fed children was 1.5% and 4.7% respectively (P = 0.063); the difference was likely due to the higher mothers' HBeAg-positive rate in formula-fed group (formula-fed 49.0% vs. breastfed 15.9%, P<0.001). Further logistic regression analyses showed that breastfeeding was not associated with the HBV infection in the children, adjusting for the effect of maternal HBeAg status and other factors different between the two groups.

Conclusions/Significance

Under the recommended prophylaxis, breastfeeding is not a risk factor for mother-to-child transmission of HBV. Therefore, clinicians should encourage HBV-infected mothers to breastfeed their infants.

Future prevention and treatment of chronic hepatitis B infection

Vaccination for hepatitis B virus (HBV) infection and treatment for chronic hepatitis B, while effective for primary prevention and control of the disease, still have their limitations. Global coverage of HBV immunization needs improvement. Several patient populations are noted to have suboptimal seroprotective rates after HBV vaccination. There are currently several potential new vaccines undergoing animal and human studies, most notably vaccines containing immunostimulatory DNA sequences. Long-term nucleoside analogue therapy is necessary in achieving permanent virologic suppression. Potential new treatments explore new mechanisms of action, including the inhibition of hepatitis B surface antigen release, targeting antifibrotic mechanism, and immunomodulation through novel interferons and therapeutic vaccines. The clinical application of potential new vaccines and therapies would enhance the prevention of HBV infection and treatment of chronic hepatitis B.

Hepatitis B virus infection and pregnancy: a practical approach

Hepatitis B virus (HBV) infection is a global problem and the world has 350 million carriers of chronic hepatitis B. Over 50 % of these have acquired their infection vertically from their mothers (mother-to-child transmission [MTCT]). Majority (>90 %) of vertically-acquired infection results into chronic infection, due to induction of an immune-tolerant state. Hence, management of chronic HBV during pregnancy and strategies to prevent MTCT would go a long way in global control of HBV infection and the morbidity and mortality associated with it. However, chronic HBV infection in pregnancy presents a unique challenge, because of existence of a complex relationship between the physiological changes of pregnancy and the pathophysiological response of body to HBV. This relationship may lead to a varied presentation of the patient to the doctor depending on the period of her pregnancy and stage of her liver disease. Each of these modes of presentation raises issues that need to be addressed for successful maternal and fetal outcome, including prevention of MTCT of HBV. This review will try to give a practical approach in addressing these issues.