Hepatitis B immunoprophylaxis failure and the presence of hepatitis B surface gene mutants in the affected children

Hepatitis B virus (HBV) infection is usually vertically transmitted from the mother to child during birth in Asian countries. Despite immunization, immunoprophylaxis failure is well‐documented. The aim of the study was to study immunoprophylaxis failure rate in the cohort of infants delivered by chronic HBV‐infected mothers and to determine risk factors for failure. This was an observational study involving chronic hepatitis B infected mothers seen at a tertiary care center in Singapore between June 2009 and December 2013. Infants born to these mothers were recruited after they had completed the recommended vaccination schedule. Serological testing for the children was performed 3 months after completion of the last dose of vaccine. HBV surface gene sequencing was carried out if HBV DNA was detectable in the children. Among the 161 mothers enrolled, most were HBeAg negative. HBeAg positive mothers were younger and had a significantly higher viral load (6.5 log) as compared to HBeAg negative mothers (1.35 log) (P