Vertical transmission of hepatitis B virus: propositions and future directions

Hepatitis B virus infection, infertility, and assisted reproduction

BACKGROUND: Hepatitis B virus (HBV) is one of the most widespread viruses worldwide and a major cause of hepatitis, cirrhosis, and hepatocellular carcinoma. Previous studies have revealed the impacts of HBV infection on fertility. An increasing number of infertile couples with chronic hepatitis B (CHB) virus infection choose assisted reproductive technology (ART) to meet their fertility needs. Despite the high prevalence of HBV, the effects of HBV infection on assisted reproduction treatment remain limited and contradictory. OBJECTIVE: The aim of this study was to provide a comprehensive overview of the effect of HBV infection on fertility and discuss its effects on pregnancy outcomes, vertical transmission, pregnancy complications, and viral activity during ART treatment. METHODS: We conducted a literature search in PubMed for studies on HBV infection and ART published from 1996 to 2022. RESULTS: HBV infection negatively affected fertility in both males and females. Existing research shows that HBV infection may increase the risk of pregnancy complications in couples undergoing assisted reproduction treatment. The impact of HBV infection on the pregnancy outcomes of ART is still controversial. Current evidence does not support that ART increases the risk of vertical transmission of HBV, while relevant studies are limited. With the development of ART, the risk of HBV reactivation (HBVr) is increasing, especially due to the wide application of immunosuppressive therapy. CONCLUSIONS: Regular HBV infection screening and HBVr risk stratification and management are essential to prevent HBVr during ART. The determination of optimal strategy and timing of prophylactic anti-HBV therapy during ART still needs further investigation.

Seroconversion among children with HBsAg-positive mothers in Indonesia and factors affecting the anti-HBs titers

Background and aim

Around 2% of newborns are at risk of hepatitis B virus (HBV) infection from their mothers. To prevent this, infants born to HBsAg-positive mothers are given hepatitis B immune globulin (HBIG) and hepatitis B (HB) vaccine as immunoprophylaxis. This study aims to investigate the efficacy of immunoprophylaxis in infants born to HBsAg-positive mothers and the contributing factors.

Methods

The study was conducted on a group of 87 children, ranging from nine months to under 36 months, born to HBsAg-positive mothers and received immunoprophylaxis within 24 h after birth followed by a national immunization schedule at the Community Health Center (CHC) in three administrative cities of DKI Jakarta. We measured the levels of HBsAg and anti-HBs, and utilized ordinal logistic regression models to identify factors that influence the anti-HBs titers after vaccination.

Results

Out of 87 children, only one child had positive HBsAg results. The data showed that 88.5% of the children had seroprotection with anti-HBs levels ≥10 mIU/mL. Additionally, 48.3% of the children had a high protective response with anti-HBs levels ≥100 mIU/mL, while 11.5% had a non-protective response. Children under one year of age, with a family history of HBV carriers, and who received five doses of the HB vaccine exhibited higher levels of anti-HBs titer category with adjusted OR 3.9 (95%CI: 1.3-11.6), 5.3 (95%CI: 1.1-27.4), and 8.3 (95%CI: 2-34.8), respectively.

Conclusion

The administration of HBIG and HB vaccine successfully prevented vertical transmission, resulting in a high seroprotection rate.

Maternal-to-Child Transmission of Hepatitis B Virus and Hepatitis Delta Virus

Maternal-to-child transmission of hepatitis B virus (HBV) and hepatitis delta virus (HDV) can lead to the risk of progressive liver disease in infants, but fortunately effective interventions exist to decrease transmission. Counseling on the risk of maternal-to-child transmission, care pathways to decrease transmission, and the implications of HBV and HDV on pregnancy outcomes are the key components of caring for pregnant people living with HBV and HDV.

Prevalence of hepatitis B virus amongst refugees, asylum seekers and internally displaced persons in low- and middle-income countries: A systematic review

Hepatitis B, caused by the hepatitis B virus (HBV), is a global public health issue that affects 290 million people worldwide. Most people with hepatitis B are in low- and middle-income countries (LMIC), where health systems and resources are often constrained. Refugees, asylum seekers and internally displaced persons (IDPs) often face barriers in seeking health care and are a priority population at risk of hepatitis B. No systematic review to date has evaluated the prevalence of hepatitis B amongst refugees in in LMIC. We undertook a systematic review of the literature identifying 28 studies addressing this topic. Though few studies on this topic exist, the available evidence suggests a high prevalence amongst refugees in LMIC, with wide variation between and within countries. Possible risk factors contributing to hepatitis B include unsafe injections, low immunization coverage, low awareness, mother-to-child transmission, and limited health services. Further study is needed to better understand the prevalence and risk factors for hepatitis B amongst refugees in LMIC, to inform public health responses. Vulnerable populations such as refugees are an important group to consider in national and global efforts to eliminate hepatitis B.

Longitudinal monitoring of post-vaccination immunity against hepatitis B in children after standard immunization in the first year of life and optimization of vaccination strategy

A clinical and laboratory examination of 62 children aged 10—17 years vaccinated against hepatitis B according to the standard scheme (0—1—6 months) in the first year of life strictly according to the National Calendar of preventive vaccinations in a standard dose (10 micrograms of recombinant HBsAg) with a monocomponent vaccine was carried out.

The majority of children (58%) had indicators of seroconversion of HBsAg — anti-HBs-antibodies. This indicates the fact of long-lasting Grund immunity — 10—17 years after timely 3-fold immunization against hepatitis B according to the standard scheme at a standard dose (10 mcg of recombinant HBsAg in the first year of life in the absence of Wooster immunization (revaccination) in subsequent age periods, including children with a burdened premorbid background (87.1% among those observed). Since among those observed were children with invasive medical interventions (50%), the established fact reflects the protective effect of standard Grund immunization even in children at risk — with a positive parenteral history. At the same time, the total assessment of serological and molecular biological results found that after triple immunization against hepatitis B according to the standard scheme in the first year of life, out of 62 children aged 10—17 years, the proportion of seronegative was 42%. Low levels of antibodies (10—100 IU/l) were detected in 43% of cases, high (100—1000 IU/l) — in 15% of cases. No child had an antibody level exceeding >1000 IU/l. These results require the development of new approaches to immunization of children against hepatitis B with mandatory revaccination at an older age.

Neutralization of hepatitis B virus with vaccine-escape mutations by hepatitis B vaccine with large-HBs antigen

Although the current hepatitis B (HB) vaccine comprising small-HBs antigen (Ag) is potent and safe, attenuated prophylaxis against hepatitis B virus (HBV) with vaccine-escape mutations (VEMs) has been reported. We investigate an HB vaccine consisting of large-HBsAg that overcomes the shortcomings of the current HB vaccine. Yeast-derived large-HBsAg is immunized into rhesus macaques, and the neutralizing activities of the induced antibodies are compared with those of the current HB vaccine. Although the antibodies induced by the current HB vaccine cannot prevent HBV infection with VEMs, the large-HBsAg vaccine-induced antibodies neutralize those infections. The HBV genotypes that exhibited attenuated neutralization via these vaccines are different. Here, we show that the HB vaccine consisting of large-HBsAg is useful to compensate for the shortcomings of the current HB vaccine. The combined use of these HB vaccines may induce antibodies that can neutralize HBV strains with VEMs or multiple HBV genotypes.

Pharmacological approaches to prevent vertical transmission of HIV and HBV

INTRODUCTION

Mother-to-child transmission (MTCT) is mainly responsible for the global pediatric HIV and HBV epidemic. Vertical transmission can be prevented and reduced through a series of interventions at the primary healthcare level, including extensive screening of pregnant women, administration of antivirals or immune-based treatments, counselling on type of delivery and breastfeeding.

AREAS COVERED

In this narrative review, approved therapeutic options for the treatment of pregnant women living with HIV or HBV are discussed with special focus on efficacy and safety profiles of each agent or drug class examined. The search was performed using Medline (via PubMed), Web of Science, and Google Scholar to identify studies assessing vertical transmission of both HIV and HBV.

EXPERT OPINION

Elimination of MTCT of both infections is firmly endorsed by major global commitments and the integration of tailored preventive interventions into maternal and newborn health services is of strategical importance to achieve this critical target. However, further research centered on antiviral-based and immunization trials among pregnant women is urgently needed to mitigate the risk of maternal and neonatal adverse outcomes, effectively prevent transmission to the offspring and finally eliminate the pediatric HIV and HBV epidemic, one of the key global health challenges of our time.