Hepatitis B virus infection assessed 3 to 18 years after vaccination in Cuban children and adolescents born to HBsAg-positive mothers

An overview of occult hepatitis B infection (OBI) with emphasis on HBV vaccination

Background

The prevalence of chronic hepatitis B virus (HBV) poses a significant threat to the lives of 257 million individuals globally, potentially resulting in severe outcomes such as liver cirrhosis or hepatocellular carcinoma. Among the existing preventive measures, yeast-derived vaccines have proven to be the most efficacious approach in combatting hepatitis B. Nonetheless, as scientific inquiries focus more on occult HBV infection (OBI) in vaccinated persons and the lingering risk of vertical transmission affecting 10-30 % of babies born to HBsAg-positive mothers, there is a growing apprehension regarding the inability of HBV vaccines to ensure complete immunity. This study aims to offer a more comprehensive understanding of the implications of widespread HBV vaccination initiatives on OBI while tackling the primary limitations associated with current vaccine formulations.

Methods

The exploration was conducted on PubMed, Scopus, and Web of Science databases to pinpoint research on OBI within vaccinated cohorts. A sum of 76 suitable studies was recognized.

Discussion

Multiple studies have documented the occurrence of OBI in fully vaccinated individuals, including both the general population and high-risk groups, such as newborns born to HBsAg-positive mothers. Factors contributing to vaccine failures include low-level anti-HBs antibodies, high maternal viral loads in mother-to-child transmission cases, as well as the presence of vaccine escape mutants and heterologous HBV genotypes. However, further research is needed to precisely understand the impact of active immunization on the emergence of OBI in vaccinated populations. Nonetheless, it is apparent that the advancement of more effective HBV vaccines could potentially lead to the extinction of HBV.

Global prevalence of occult HBV infection in children and adolescents: A systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Occult HBV infection (OBI) is a specific form of hepatitis B virus (HBV) infection and has the possibility of developing into hepatocellular carcinoma (HCC) in adults. This study aimed to estimate the global prevalence of occult HBV infection in children and adolescents.

MATERIALS AND METHODS

We systematically searched PubMed, Embase, Web of Science, and Cochrane databases for relevant studies on the prevalence of OBI in children and adolescents. Meta-analysis was performed using STATA 16 software.

RESULTS

Fifty studies were included. The overall prevalence of OBI in children and adolescents was 7.5% (95% CI: 0.050-0.103). In different risk populations, OBI prevalence was remarkably high in the HIV-infected population (24.2%, 95% CI: 0.000-0.788). The OBI prevalence was 0.8% (95% CI:0.000-0.029) in the healthy population, 3.8% (95% CI:0.012-0.074) in the general population, and 6.4% (95% CI: 0.021-0.124) in children born to HBsAg-positive mothers. Based on different serological profiles, the prevalence of OBI in HBsAg-negative and anti-HBc-positive patients was 6.6% (95% CI: 0.016-0.136), 3.0% (95% CI: 0.009-0.059) in HBsAg-negative and anti-HBc-negative patients, 4.6% (95% CI: 0.015-0.088) in HBsAg-negative and anti-HBs-positive patients, and 3.7% (95% CI: 0.001-0.102) in HBsAg-negative and anti-HBs-negative patients.

CONCLUSIONS

Despite HBV vaccination and hepatitis B immunoglobulin (HBIG), OBI is common in children and adolescents in high-risk groups.

Overt and occult hepatitis B infection after neonatal vaccination: mother-to-infant transmission and HBV vaccine effectiveness

OBJECTIVES

Overt and occult hepatitis B infection (HBI) among mothers and infants were investigated, and the effectiveness of vaccination against HBI was evaluated based on transmission types.

METHODS

A hospital-based cohort was built with 2,734 mothers and 330 mother-infant pairs. Their demographic data were collected. Serological HBV markers, nested-PCR for HBV genes, viral load detection, and phylogenetic analysis were done.

RESULTS

The overall prevalence of HBI among mothers was 12.1% (330/2,734), with 10.4% for the overt type and 1.8% for the occult type. In 330 out of 1,650 (20%) mother-infant pairs, the overall, type-I (from overt mother to overt infant), type-II (from overt mother to occult infant), and type-Ⅲ (from occult mother to occult infant) transmissions were 1.9% (1/54), 5.6% (3/54) and 0.0% (0/7). The refinement of HBI classification improved the estimate of vaccine effectiveness against HBI from 74.4%-80.9% to 94.4%, which was more prominent for type-II. One mother-infant pair with type-II transmission shared nearly identical complete sequences. However, the high rate of lost-to-follow-up could not be ignored.

CONCLUSIONS

During the transition period, HBV is mainly transmitted from the overt type of HBI mother to infant. Intensive prenatal screening for mothers is vital.