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

Weak Adoption and Performance of Hepatitis B Birth-Dose Vaccination Programs in Africa: Time to Consider Systems Complexity?-A Scoping Review

The persistent burden of chronic hepatitis B among ≤5-year-old children in Africa suggests missed opportunities for controlling mother-to-child transmission (MTCT) of the hepatitis B virus (HBV). This scoping review maps the evidence base on the risk of HBV MTCT, the status of HBV MTCT mitigation strategies including hepatitis B birth-dose vaccination, and the role of systems complexity on the suboptimal adoption and performance of hepatitis B birth-dose vaccination programs in Africa. Overall, 88 peer-reviewed and grey literature sources published between 2000-2022 were included in this review. The growing evidence base consistently argues for a heightened risk of HBV MTCT amidst the HIV co-epidemic in the region. Without universal HBV screening programs integrated within broader antenatal care services, current selective hepatitis B birth-dose vaccination is unlikely to effectively interrupt HBV MTCT. We underscore critical health systems-related barriers to universal adoption and optimal performance of hepatitis B birth-dose vaccination programs in the region. To better conceptualize the role of complexity and system-wide effects on the observed performance of the program, we propose an adapted systems-based logic model. Ultimately, exploring contextualized complex systems approaches to scaling-up universal hepatitis B birth-dose vaccination programs should form an integral part of the regional research agenda.

Enhancing interventions for prevention of mother-to-child- transmission of hepatitis B virus

Prevention of mother-to-child transmission of hepatitis B virus (HBV) infection is a cornerstone of efforts to support progress towards elimination of viral hepatitis. Current guidelines recommend maternal screening, antiviral therapy during the third trimester of high-risk pregnancies, universal and timely HBV birth dose vaccination, and post-exposure prophylaxis with hepatitis B immunoglobulin for selected neonates. However, serological and molecular diagnostic testing, treatment and HBV vaccination are not consistently deployed, particularly in many high endemicity settings, and models predict that global targets for reduction in paediatric incidence will not be met by 2030. In this article, we briefly summarise the evidence for current practice and use this as a basis to discuss areas in which prevention of mother-to-child transmission can potentially be enhanced. By reducing health inequities, enhancing pragmatic use of resources, filling data gaps, developing advocacy and education, and seeking consistent investment from multilateral agencies, significant advances can be made to further reduce vertical transmission events, with wide health, societal and economic benefits.

Cost-effectiveness of tenofovir prophylaxis during pregnancy for the elimination of mother-to-child transmission of the hepatitis B virus: real-world analysis from Thailand

OBJECTIVE

Despite implementing hepatitis B immunoglobulin (HBIG) and vaccination, data suggest it would not be sufficient to reach the elimination targets. Tenofovir disoproxil fumarate (TDF) has been added to the Thai national standards of care for prevention of transmission of the hepatitis B virus during birth. To optimise national strategies in Thailand, we assessed TDF's effectiveness for prevention of mother-to-child transmission and conducted cost-effectiveness analyses of different TDF-based strategies.

RESEARCH DESIGN AND METHODS

We retrospectively reviewed medical records of mother and infant pairs whose mothers were positive for hepatitis B e-antigen (HBeAg) and received TDF to prevent maternal transmission of viral hepatitis B during 2018-2020. Based on the available data on transmission rate, we also applied a decision tree to estimate the cost-effectiveness of different TDF-based strategies to eligible mothers. These included: (1) HBIG for all hepatitis B virus (HBV) exposed infants; (2) HBIG for only infants of HBeAg-positive mothers ('HBIG for e-positive') and (3) without HBIG to infants ('HBIG-free'). The incremental cost-effectiveness ratio between the different strategies and baseline intervention without TDF was calculated. The one-way sensitivity analysis was used to adjust prevalence of HBeAg-positive mothers, cost of HBIG, cost of TDF and transmission rate.

RESULTS

Of 223 infants enrolled, 212 (95.0%) received HBIG, while 11 (5.0%) did not. None of the infants had chronic HBV infection. The most cost-saving intervention was 'HBIG-free' followed by 'HBIG for e-positive'. The one-way sensitivity demonstrated that the results were reasonably robust to changes. The cost-saving was greater with a higher hepatitis B virus surface antigen (HBsAg) prevalence. The HBIG-free strategy remained best at 0%-1.4% transmission rates, meeting the additional target for eliminations.

CONCLUSION

The study is the first cost-effectiveness analyses to provide evidence supporting an HBIG-free strategy in an antiviral era. This approach should be considered to prevent mother-to-child transmission in resource-constrained settings, particularly in countries with a high HBsAg prevalence.

Post-vaccination serologic testing of infants born to hepatitis B surface antigen-positive mothers is more cost-effective in Zhejiang Province, China: A Markov chain analysis

To evaluate the cost-effectiveness of the post-vaccination serologic testing (PVST) plus active-passive immunoprophylaxis of infants born to hepatitis B surface antigen (HBsAg)-positive mothers, a Markov model was constructed by R 4.0.1 to compare the current strategy (three-dose HepB plus HBIG) and the PVST strategy (post-vaccination serologic testing plus the current strategy) for infants of HBsAg-positive mothers. Costs and utility scores were assessed from a field survey. Other model inputs were extracted from published literature and unpublished data from the Zhejiang provincial center for disease control and prevention (Zhejiang CDC). We calculated the incremental cost-effectiveness ratio (ICER) as the main result within 1-year cycle length with a 81 horizon among 50,000 infants and performed one-way sensitivity analysis and probabilistic sensitivity analysis to explore the reliability of outcome. The ICER was -4130.18 yuan/quality-adjusted life year (QALY) for the PVST strategy compared with the current strategy from the societal perspective. It was estimated that the PVST strategy would save about 3,809,546 yuan and prevent loss of 922.37 QALYs within 81 cycles among 50,000 infants. ICER was most sensitive to the discount rate, and the cost-effectiveness acceptability curves showed that the PVST strategy reached a probability of being 100% cost-effective below willing to pay (107,624 yuan). In conclusion, the PVST strategy had increased the utility and reduced cost among infants born to HBsAg-positive mothers. The PVST strategy is a more cost-effective choice for infants born to HBsAg-positive mothers than the current strategy, and further promotion of the PVST project is recommended.

Developing an Effective Peptide-Based Vaccine for COVID-19: Preliminary Studies in Mice Models

Coronavirus disease 2019 (COVID-19) has caused massive health and economic disasters worldwide. Although several vaccines have effectively slowed the spread of the virus, their long-term protection and effectiveness against viral variants are still uncertain. To address these potential shortcomings, this study proposes a peptide-based vaccine to prevent COVID-19. A total of 15 B cell epitopes of the wild-type severe acute respiratory coronavirus 2 (SARS-CoV-2) spike (S) protein were selected, and their HLA affinities predicted in silico. Peptides were divided into two groups and tested in C57BL/6 mice with either QS21 or Al(OH)₃ as the adjuvant. Our results demonstrated that the peptide-based vaccine stimulated high and durable antibody responses in mice, with the T and B cell responses differing based on the type of adjuvant employed. Using epitope mapping, we showed that our peptide-based vaccine produced antibody patterns similar to those in COVID-19 convalescent individuals. Moreover, plasma from vaccinated mice and recovered COVID-19 humans had the same neutralizing activity when tested with a pseudo particle assay. Our data indicate that this adjuvant peptide-based vaccine can generate sustainable and effective B and T cell responses. Thus, we believe that our peptide-based vaccine can be a safe and effective vaccine against COVID-19, particularly because of the flexibility of including new peptides to prevent emerging SARS-CoV-2 variants and avoiding unwanted autoimmune responses.

Antenatal hepatitis B screening in Nigeria: A comparative analysis with syphilis and HIV

Nigeria has adopted routine screening of pregnant women for hepatitis B virus (HBV) as part of the interventions to eliminate its vertical transmission. However, there is a dearth of evidence on the coverage of routine antenatal HBV screening as recommended in the national guidelines. This study examined the antenatal HBV screening rate and the positivity rate compared with syphilis and HIV. We conducted a descriptive analysis of the 2019 national HIV/AIDS health sector data. The study included approximately 2.8 million pregnant women who received antenatal care (ANC) in over 6000 health facilities providing prevention of mother-to-child transmission of HIV services in Nigeria. Of the ANC clients, 0.2 million (7.2%) were screened for HBV. At the zonal level, the South West had the highest HBV screening rate (19%), while the lowest rate was in the North East (2.5%). The percentage of pregnant women screened for HBV was lower than those screened for syphilis (16.3%) and HIV (90.3%). Among those screened for HBV, the positivity rate was 5%. The HBV positivity rate ranged from 8.5% in the North Central zone to 1.3% in the South East zone. The positivity rates for syphilis and HIV were 0.4% and 0.5%, respectively. Our results indicate a low antenatal HBV screening rate and a wide disparity compared with HIV and syphilis. This finding highlights the need to understand and address the barriers affecting routine antenatal HBV screening and to strengthen the integration of HBV services into the HIV program in Nigeria.