Effectiveness of timely hepatitis B birth dose vaccination to prevent mother-to-child transmission in Ethiopia
Nega Berhe, Hailemichael Desalegn, Hiwot Mengistu, Dawit Birhane, Birhanu Kebede, Minwuyelet Maru, Fikadu Girma, Delayehu Bekele, Tadesse Gure, Humed Yaid, Semir Abdi, Yusuke Shimakawa, Asgeir Johannessen, Shevanthi Nayagam, , Gibril Ndow, Umberto D’Allessandro, Bakary Dibba, Lamin Bojang, Coumba Toure-Kane, Gora Lo, Assane Diouf, Adama Faye, Abou Ba, Tim Hallett, Maud Lemoine, John WardAbstract
Background
Mother-to-child transmission (MTCT) is an important route of new hepatitis B virus (HBV) infections. In Africa, limited and conflicting data on the effectiveness of hepatitis B birth dose vaccination (HepB-BD) have contributed to fragmented adoption and sub-optimal implementation. We aimed to assess the effectiveness of timely HepB-BD in preventing HBV MTCT in Ethiopia.
Methods
We conducted a multi-centre cross-sectional observational study in Ethiopia from May 2022 to June 2024. We identified mothers who had tested positive for hepatitis B surface antigen (HBsAg) during pregnancy and assessed mother-infant pairs at 6-12 months post-partum for HBV MTCT. We stratified effectiveness of HepB-BD by maternal risk profile (HBV DNA level, hepatitis B e-antigen (HBeAg) status).
Results
The analysis included 387 children born to HBV-positive, HIV-negative mothers who had completed routine HBV vaccination (HepB3). The median age of infant testing was 10 months (IQR 7.0-11). Overall MTCT risk was 5.2% (95% CI 3.4,7.8). MTCT was significantly lower among infants receiving HepB-BD alone (0/39, 0% [95% CI 0-9.0]) compared to those without immunoprophylaxis at birth (20/131, 15.3% [95% CI 10.1-22.4]) (p = 0.009). No transmission occurred with HepB-BD plus HBIg (0/217, 0% [95% CI 0-1.7]). Maternal viral load >200,000 IU/ml (AOR 16.6, 95% CI 4.82,57.19) and HBeAg positivity (AOR 4.21, 95% CI 1.08,16.44) were associated with increased MTCT risk amongst infants without immunoprophylaxis at birth.
Conclusions
In Ethiopia, the current vaccination series starting at 6 weeks is insufficient to prevent HBV MTCT. Timely HepB-BD is highly effective in reducing HBV MTCT and should be prioritised for scale-up in Africa.