Assessment of the timely administration of the hepatitis B and BCG birth dose and the primary infant vaccination schedule in 2015-2016 in the Mekong Delta, Viet Nam.

Introduction: Vietnam is implementing hepatitis B (HBV) birth dose (BD) vaccination since 2003 but coverage remains low, especially in the Mekong River Delta. This study aimed to determine the coverage of the HBV BD vaccination, to identify socio-demographic factors influencing HBV BD, and to assess reasons for non-immunization of neonates.

Methods: A cross-sectional survey was conducted in 2015-2016. Mothers from 526 children aged 6-11 months living in 3 provinces in the Mekong River Delta - representing respectively urban, rural and remote area - were interviewed at home and infant vaccination documents were checked. The three-stage sampling method was adapted from WHO 30-cluster sampling. Predictors of HBV BD administration were identified with multiple regression analysis.

Results: The overall HBV BD coverage (within 24 h) was 46.6% (compared to 44.5% for BCG) and was significantly higher in remote or rural than in urban area (OR 1.87 and 3.36, respectively), and in children whose father had a higher educational level (OR 2.76; 2.29 and 1.86, respectively, for master degree, bachelor and secondary school) as compared to a lower level. Main reasons for not having received HBV BD mentioned by parents were vaccines not offered by health care workers (53.0%), and illness of the infant (27.2%).

Conclusion: Although Vietnam started HBV BD vaccination more than 10 years ago, the coverage and timeliness need to improve to reach WHO targets (95% within 24 h after birth). Better training and information of health care workers, and better protocols ensuring timely HBV BD could address these vaccine administration thresholds.