Duration of immune protection after hepatitis B vaccine in newborns from HBsAg-positive carrier mothers

A group of 43 healthy neonats born from HBsAg-positive mothers were evaluted for the presence of protective HBsAb titre after administration of hepatitis B plasma-derived vaccine and hepatitis B hyperimmune-globulin. At 36 months of life we found that a significant number of children had a low HBsAb serum level. This suggests that a close serologic follow-up is necessary to evaluate the optimal timing for the administration of a booster dose of the vaccine.