Determinants of timely administration of the birth dose of hepatitis B vaccine in Senegal in 2019: Secondary analysis of the demographic and health survey.

In developing countries, hepatitis B is spread primarily by the perinatal or horizontal route. Thus, the Senegalese government recommends administering the birth dose of the hepatitis B vaccine (HepB0) within 24 hours of birth. The objective was to identify the determinants of timely administration of HepB0 in Senegal in 2019. A secondary analysis of the demographic and health survey was carried out. The study population consisted of children aged 12 to 23 months. A cluster survey, stratified in urban and rural areas, drawn at two stages, was carried out. Individual interviews were conducted. Logistic regression was applied to estimate the adjusted odds ratio (aOR) and their 95% confidence interval. In total, 1130 children were included. Among them, 48.1% were born to mothers aged 25 to 34, 46.8% were male and 82.6% were born in health facilities. The average time between birth and HepB0 administration was 13.1±46.6 days. The median is 0 days [IQR: 0-12] with a minimum of 0 days and a maximum of 414 days. Among 747 children vaccinated, only 65.2% were vaccinated within 24 hours of birth. The determinants were maternal age of at least 35 years (aOR = 2.03 [1.29-3.20]), primary education of the mother (aOR = 1.94 [1.13-3. 35]), at least four antenatal care visits (aOR = 1.74 [1.12-2.69]), belonging to the central (ORa = 0.22 [0.11-0.44]) and northern regions (aOR = 0.18 [0.08-0.40]), and delivery in a health facility (aOR = 3.42 [1.90-6.15]). Education and keeping girls in school, local postnatal care in hard-to-reach regions, promotion of antenatal acre and delivery in a health facility should improve the timeliness of HepB0 vaccination.