A prospective, multicenter study of hepatitis B birth-dose vaccine with or without hepatitis B immunoglobulin in preventing mother-to-child transmission of hepatitis B virus in Ethiopia

Abstract

Background: Historically, mother-to-child transmission (MTCT) of hepatitis B virus (HBV) was considered uncommon in Africa, leading to a reluctant attitude to birth-dose HBV vaccination on the continent. As a randomized trial would be unethical, real-life data are needed to assess the effect of HBV birth-dose vaccine in Africa.

Methods: A multicenter, prospective, observational study of hepatitis B surface antigen (HBsAg)-positive pregnant women and their infants was carried out in Ethiopia, from January 2019 to May 2021. Pregnant women were screened for HBsAg and HIV as part of routine antenatal care and/or delivery, and HBsAg-positive HIV-negative pregnant women were included in the study. HBV birth-dose vaccine and hepatitis B immunoglobulin (HBIg) were recommended but not all newborns received it as it was not national policy. All infants, however, received the pentavalent HBV vaccine at 6, 10, and 14 weeks of age. Vaccination status was confirmed from delivery ward charts and infant vaccination certificates. Infants were tested for HBsAg at 9 months of age and a positive result was taken as evidence of MTCT.

Findings: Of 290 HBsAg-positive pregnant women, 168 mother/infant pairs returned for their 9-month follow-up visit and were included in this analysis. Two of 112 (1.8 %) infants who received birth-dose vaccine with HBIg, and 2 of 23 (8.7 %) who received birth-dose vaccine alone were HBsAg positive at nine months of age, compared to 8 of 33 (24.2 %) who received neither vaccine nor HBIg at birth (p = 0.002). High maternal viral load (>200,000 IU/ml; adjusted odds ratio [AOR] 10.4; 95 % confidence interval [CI] 1.2-92.1) and not receiving HBV birth-dose vaccine nor HBIg (AOR 29.2; 95 % CI 4.0-211.3) were independent predictors of MTCT.

Interpretation: Birth-dose HBV vaccine with or without HBIg significantly reduced the risk of MTCT of HBV in Ethiopia. Improved coverage of birth-dose HBV vaccine should be an urgent priority.

Keywords: Hepatitis B virus; Pregnancy; Sub-Saharan Africa; Transmission; Vaccination.