A non-randomized vaccine effectiveness trial of accelerated infant hepatitis B immunization schedules with a first
Daniel Ekra1, Karl-Heinz Herbinger, Seydou Konate
1Institut National d'Hygiène Publique (INHP), Abidjan, Cote d'Ivoire.
Insights
Hepatitis B vaccination at birth may benefit African infants, though both birth and delayed schedules showed high transmission rates in infants born to HBeAg-positive mothers. Further research is needed to confirm the efficacy of early hepatitis B vaccination.
Area of Science:
- Public Health
- Vaccinology
- Pediatrics
Background:
- Hepatitis B vaccination is not routinely initiated at birth in most African countries.
- The current hepatitis B vaccination schedule in Côte d'Ivoire starts at 6 weeks of age.
- Infant hepatitis B virus (HBV) transmission remains a concern in regions with delayed vaccination initiation.
Purpose of the Study:
- To compare the efficacy of a hepatitis B vaccine schedule initiated at birth (0, 6, 14 weeks) versus the standard schedule (6, 10, 14 weeks) in preventing infant HBV transmission.
- To evaluate HBV transmission rates in infants based on maternal HBeAg status.
- To assess the effectiveness of different hepatitis B vaccination timings in African infants.
Main Methods:
- A non-randomized controlled trial was conducted with pregnant women in Abidjan.
- Infants were assigned to either a birth dose cohort or a 6-week delayed dose cohort.
- Hepatitis B surface antigen (HBsAg) positivity was assessed at 9 months of age, with stratification by maternal HBeAg status.
Main Results:
- Overall HBsAg positivity at 9 months was 0.5% in both the birth and 6-week cohorts, with all positive infants born to HBeAg-positive mothers.
- Among infants born to HBeAg-positive mothers, HBsAg positivity was 37.5% in the birth cohort and 58.8% in the 6-week cohort.
- Both vaccination schedules demonstrated effectiveness in preventing the majority of infant HBV transmissions but showed high failure rates in infants of HBeAg-positive mothers.
Conclusions:
- While a birth dose of the hepatitis B vaccine may offer benefits to African infants, current schedules have limitations, particularly for infants born to HBeAg-positive mothers.
- Both evaluated hepatitis B vaccination schedules were largely effective but did not fully prevent transmission in high-risk infants.
- Additional research is required to determine optimal hepatitis B vaccination strategies for African populations, especially concerning high-risk pregnancies.
Abstract:
Most African countries do not initiate hepatitis B vaccination at birth. We conducted a non-randomized controlled trial comparing hepatitis B vaccination given at age 0, 6, and 14 weeks versus the current Côte d'Ivoire schedule of 6, 10, and 14 weeks. Pregnant women were enrolled at four health centers in Abidjan. At age 9 months, 0.5% of infants in both the birth and 6-week cohorts were positive for HBsAg and all were born to HBeAg-positive women. Among infants of HBeAg-positive mothers, 9 of 24 (37.5%) in the birth cohort and 10 of 17 (58.8%) in the 6-week cohort were HBsAg positive (adjusted OR, 2.7; 95% CI: 0.7-11.0). While both vaccine schedules prevented most cases of infant HBV transmission, both also had high failure rates among infants of HBeAg-positive mothers. African infants may benefit from a birth dose but additional studies are needed to verify this hypothesis.
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