Passive-active immunisation of neonates of HBsAg positive carrier mothers: preliminary observations.

Screening of pregnant women for hepatitis B surface antigen (HBsAg) in three areas of Holland led to the identification of HBsAg carriers, 20 of whom were subsequently delivered. Within two hours after birth all infants received hepatitis B immune globulin (0.5 ml/kg body weight) and, after randomisation, hepatitis B vaccine (10 micrograms) was given either at 0, 1, and 2 months of age or at 3, 4, and 5 months of age, the latter concomitantly with DPTP vaccination. Eighteen infants complying with the protocol were followed up for at least six months. No side effects were observed after either passive or active immunisation. All infants developed high concentrations of anti-HBs antibodies; no interference of high dose passive immunisation with active immunisation was observed. Concentrations of anti-HBs at three months were significantly lower in infants given delayed active immunisation than in those given early active immunisation. These data suggest that passive-active immunisation against hepatitis B virus infection is well tolerated by neonates under 3 months of age and that both early and late active immunisation in combination with passive immunisation will result in excellent anti-HBs production.