Impact of Introducing Hepatitis B Birth Dose Vaccines into the Infant Immunization Program in Burkina Faso: Study Protocol for a Stepped Wedge Cluster Randomized Trial (NéoVac Study)

Costs of integrating hepatitis B screening and antiviral prophylaxis into routine antenatal care in Burkina Faso: Treat all versus targeted strategies

OBJECTIVE

Economic feasibility of eliminating mother-to-child transmission (MTCT) of hepatitis B virus (HBV) in highly endemic African countries remains uncertain. Prevention of MTCT (PMTCT) involves screening pregnant women for hepatitis B surface antigen (HBsAg), identifying those with high viral loads or hepatitis B e antigen (HBeAg), and administering tenofovir prophylaxis to high-risk women. We estimated the costs of integrating PMTCT services into antenatal care in Burkina Faso, based on four different strategies to select women for tenofovir prophylaxis: (1) HBV DNA (≥200 000 IU/mL), (2) HBeAg, (3) hepatitis B core-related antigen rapid diagnostic test (HBcrAg-RDT) and (4) all HBsAg-positive women.

METHODS

Using a micro-costing approach, we estimated the incremental economic cost of integrating each strategy into routine antenatal care in 2024, compared to neonatal vaccination alone. Sensitivity analyses explored variations in prevalence, service coverage, test and tenofovir prices.

RESULTS

HBcrAg-RDT strategy was the least expensive, with a total economic cost of US$3959689, compared to HBV DNA (US$6128875), HBeAg (US$4135233), and treat-all (US$4141206). The cost per pregnant woman receiving tenofovir prophylaxis varied from US$61.88 (Treat-all) to US$1071.05 (HBV DNA). The Treat-All strategy had the lowest marginal cost due to a higher number of women on tenofovir (66928) compared to HBV DNA (5722), HBeAg (10020), and HBcrAg-RDT (7234). In sensitivity analyses, the treat-all strategy became less expensive when the tenofovir price decreased.

CONCLUSION

HBcrAg-RDT minimizes resource use and costs, representing 0.61% of Burkina Faso's 2022 health budget. This study highlights the potential economic feasibility of these strategies and provides valuable resources for conducting cost-effectiveness analyses.

Hepatitis B vaccine effectiveness among vaccinated children in Africa: a systematic review and meta-analysis

BACKGROUND

Globally, 257 million people have chronic hepatitis. Even though a safe and effective prophylactic vaccine against HBV infection has been available, it causes significant morbidity and mortality. HBV vaccines were designed to improve or modulate the host immune responses. The effectiveness of the vaccine is determined by measuring serum hepatitis B surface antibody (Anti-HBs) level. Therefore, this systematic review aimed to evaluate the effectiveness of hepatitis B vaccine among vaccinated children.

METHODS

Preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines was applied for systematically searching of different databases. Only cross-section studies measuring the level of anti-HBs of vaccinated children were included. The seroprotective level with anti-HBs > 10mIU/ml was extracted. The meta-analysis was performed using statistical software for data sciences (STATA) version 14. Effectiveness estimates were reported as a proportion of anti-HBs level. The heterogeneity between studies was evaluated using the I2 test, and I2 > 50% and/or P < 0.10 was considered significant heterogeneity. Significant publication bias was considered when Egger's test P-value < 0.10. The new castle Ottawa scale was used to assess the quality of the studies.

RESULTS

A pooled sample size of the included papers for meta-analysis was 7430. The pooled prevalence of seroprotected children was 56.95%, with a heterogeneity index (I2) of 99.4% (P < 0.001). 35% of the participants were hypo-responders (10-99mIU/ml) and 21.46% were good responders (> 100mIU/ml). Based on subgroup analysis using country of studies conducted, the highest prevalence of anti-HBs was 87.00% (95% CI: 84.56, 89.44), in South Africa, and the lowest was 51.99% (95% CI: 20.41-83.58), with a heterogeneity index I2 = 70.7% (p = 0.009) in Ethiopia.

CONCLUSION AND RECOMMENDATIONS

Hepatitis B vaccine seroprotective level in the current pooled analysis have suboptimal, which failed to demonstrate consistent effectiveness for global hepatitis B virus elimination plan in 2030. Using consistent age group may have a significant value for the decision of the HB vaccine effectiveness. A significant heterogeneity was observed both in studies conducted in Ethiopia and Egypt. Therefore, the impact of HB vaccination on the prevention of hepatitis B virus infection should be assessed regularly in those countries. Future meta-analysis is needed to investigate all possible vaccines in a separate way of reviewing, which will lead to a strong conclusion and recommendations.

Changes and gaps of global and regional disease burden of hepatitis B infection in children younger than 5 years old between 2015 and 2019: A real-world data review

Hepatitis B virus (HBV) infection has been declared an ongoing health threat, especially infections among children. We compared and updated the disease burden of HBV infection and the effectiveness of vaccination among children younger than 5 years to offer indications for hepatitis B prevention across the world. The country-level data on the prevalence of hepatitis B surface antigen (HBsAg), the coverages of hepatitis B vaccine birth-dose (HepB-BD), three-dose series (HepB3), income level, population density/size, and human development index were collected from open access databases including WHO, UNICEF, and World Bank. Comparison of the prevalence of HBsAg under 5 years old between 2015 and 2019 based on vaccination coverages was conducted by the gamma generalized linear mixed model. Globally, more than 6.3 million HBV infections were estimated in children under 5 years in 2019, compared to 10.1 million in 2015 within the 179 countries involved. The pooled average prevalence of HBsAg among children younger than 5 years decreased from 1.4% (95% confidence interval [CI]: 1.1-1.8) to 0.9% (95% CI: 0.7-1.2). The rate difference or rate ratio was -0.5% (95% CI: -0.6% to -0.3%) or 0.51(95% CI: 0.44-0.58), respectively. Countries from the African region or with lower income/population density/human development indexes bore the most significant disease burden of hepatitis B. Higher coverages of hepatitis B vaccine birth-dose or primary series correlated with significant HBsAg prevalence decreases and much-decreased ratio, independently. Hepatitis B prevention among children under 5 years has significantly been achieved while remaining the most life-threatening disease burden, unequally distributed worldwide. The hepatitis B vaccination should be prioritized for all newborns, especially in those resource-constrained countries or regions.

Tenofovir alters the immune microenvironment of pregnant women with hepatitis B virus infection: Evidence from single-cell RNA sequencing

BACKGROUND

Mother-to-child is the main route of the transmission of hepatitis B virus (HBV) infection. Tenofovir fumarate (TDF) antiviral treatment has become the most extensive choice worldwide. However, the effects of TDF treatment on the immune function of pregnant women remains unclear. Here we investigate the effect of TDF treatment on the immune microenvironment of pregnant women with HBV infection using single-cell RNA sequencing (scRNA-seq).

METHODS

Three HBV-infected pregnant women were treated with TDF and six samples were collected before and after the treatment. In total, 68,200 peripheral blood mononuclear cells (PBMCs) were extracted for 10 × scRNA-seq. The cells were clustered using t-distributed stochastic neighbor embedding (t-SNE) and unbiased computational informatics analysis.

RESULTS

The analysis identified four-cell subtypes, including T cells, monocytes, natural killer (NK) cells, and B cells, and unraveled the developmental trajectory and maturation of CD4⁺ T and CD8⁺ T cell subtypes. The cellular state and molecular features of the effector/memory T cells revealed a significant increase in the inflammatory state of CD4⁺ T cells and the cytotoxic characteristics of CD8⁺ T cells. Additionally, after TDF treatment, the monocytes showed a tendency for M1 polarization, and the cytotoxicity of NK cells was enhanced. Furthermore, the analysis of intercellular communication revealed the interaction of various subtypes of cells and the heterogeneous expression of key signal pathways.

CONCLUSIONS

The findings of this study reveal significant differences in cellular subtypes and molecular characteristics of PBMCs of pregnant women with HBV infection before and after TDF treatment and demonstrate the recovery of immune response after treatment. These findings could help develop immune intervention measures to control HBV during pregnancy and the puerperium period.

Cost-effectiveness of adding a birth dose of hepatitis B vaccine in the Dafra district of the Hauts-Bassins Region in Burkina Faso (NéoVac Study)

BACKGROUND

The World Health Organization (WHO) recommends a first hepatitis B vaccine dose within 24 h of birth (HepB-BD) to prevent mother-to-child transmission. Evidence for this strategy's economic value in Africa is limited. We assessed the costs and cost-effectiveness of adding HepB-BD to the current three-dose pentavalent schedule (HepB3) in the Dafra district of the Hauts-Bassins Region in Burkina Faso.

METHODS

Using a decision tree combined with a Markov model, we estimated the expected number of life-years (LY) and disability-adjusted life-years (DALYs) saved, incremental costs, and incremental cost-effectiveness ratios (ICER) of HepB-BD + HepB3 versus HepB3 alone in Dafra's 2017 birth cohort (n = 11,462). Institutional delivery rates, vaccine coverage, and vaccination costs from a health system perspective were estimated from field-collected data. We estimated the effectiveness of HepB-BD, age-specific transition probabilities, and horizontal transmission risks using data from previous African studies. Costs and health outcomes were discounted at an annual rate of 3%. We conducted one-way and probabilistic sensitivity analyses to assess uncertainty.

RESULTS

In the base-case analysis without discounting, HepB-BD + HepB3 yielded a net cost saving of US$18,979 and saved 163 DALYs compared with HepB3 alone. With discounting, HepB-BD + HepB3 compared with HepB3 resulted in an incremental cost of US$554 and 31 DALYs averted, translating into an ICER of US$18/DALY averted. In one-way sensitivity analyses, HepB-BD + HepB3 remained cost-effective (at the cost-effectiveness threshold of US$671 i.e. the Burkina Faso per-capita gross domestic product) for all parameter changes. However, results were very sensitive to variations in HepB-BD unit cost per vaccinated neonate and perinatal transmission risk in mothers carrying the hepatitis B e antigen. The probabilities of HepB-BD + HepB3 being cost-effective were 71.7% and 86.7%, at the cost-effectiveness thresholds of US$335 and US$671, respectively.

CONCLUSION

Introducing HepB-BD in Burkina Faso is likely to be cost-effective.