A reduction in chronic hepatitis B virus infection prevalence among children in Vietnam demonstrates the importance of vaccination.

•This nationally representative cross-sectional survey sampled children based on a stratified three-stage cluster design.•A total of 6,949 children were included in the survey analyses.•The overall HBsAg prevalence among surveyed children was 2.70%.•Unadjusted HBsAg prevalence among children with ≥3 doses of hepatitis B vaccine including a birth dose (1.75%) was significantly lower than among children with ≥3 doses of hepatitis B vaccine but lacked a birth dose (2.98%).•Childhood chronic HBV infection prevalence has been markedly reduced in Vietnam due to vaccination.