Hepatitis B vaccine birth dose coverage among hepatitis B-exposed and hepatitis B-unexposed infants: evidence from the Healthy Beginning Initiative program in Benue State, Nigeria.

INTRODUCTION: Nigeria offers universal hepatitis B birth-dose vaccine (HepB-BD) for the prevention and control of hepatitis B (HepB). While prior studies suggest low coverage of HepB-BD in Nigeria, there is a paucity of evidence on the association between the uptake of HepB-BD and maternal HepB status. This study aimed to determine HepB-BD coverage and the associated factors among infants of HepB-positive and -negative women in Nigeria.

METHODS: the study was a secondary analysis of data from the Healthy Beginning Initiative program conducted between June 2016 and October 2018 in Benue State, Nigeria. The analysis was restricted to data from a cohort of 6269 mothers who had HepB screening during pregnancy and completed the HepB infant immunization question in the post-delivery survey. The association between the coverage of HepB-BD and maternal HepB status, sociodemographic characteristics, and obstetric factors were determined using crude and adjusted relative risks.

RESULTS: about 10% of the women tested HepB positive. The coverage of HepB-BD was 64% (63.2% among infants of HepB-positive mothers and 63.8% among HepB-negative mothers). The likelihood of infants of HepB-positive mothers receiving HepB-BD was not significantly different from infants of HepB-negative mothers (aRR=0.97, 95%CI= 0.92-1.04). Among HepB-positive mothers, infants of mothers younger than 20 years (aRR=1.49, 95%CI=1.03-2.16) or those who received antenatal care (aRR=1.41, 95%CI=1.16-1.71) were more likely to receive HepB-BD, while mothers with no previous pregnancies (aRR=0.73, 95%CI=0.59-0.91) were less likely to receive HepB-BD. Among HepB-negative mothers, infants of less-educated mothers were less likely to receive HepB-BD (aRR=0.96, 95%CI=0.92-0.99), whereas infants of mothers who received antenatal care (aRR=1.23, 95%CI=1.16-1.31) or had an institutional delivery were more likely (aRR=1.29, 95%CI=1.23-1.36) to receive HepB-BD. Conclusion: our findings highlight the need to improve HepB-BD uptake, particularly among HepB-exposed infants who are at risk of perinatal transmission of HepB.