Prevention of perinatal transmission of hepatitis B virus carrier state in neonates at high risk was attempted by a combined passive and active immunization. Immediately after delivery, ten babies born to mothers who were asymptomatic carriers of hepatitis B surface antigen (HB8Ag) and seropositive for hepatitis B e antigen received an intravenous injection of F(ab’)2 fragments (200 IU) derived from hepatitis B immune globulin (HBIG). On the following day, none of them revealed detectable levels of the antibody to HB8Ag in their sera, and received an intramuscular injection of HBIG (200 IU) which was repeated at 2 and 4 months of age. Vaccination with 40 µg of purified, formalin-inactivated HB8Ag particles was given to the nine babies at three months and repeated at 4, 5, and 7 months after birth. All of them maintained detectable levels of the antibody and escaped infection throughout the first 12 months of their lives. The one baby who did not have detectable F(ab’)2 in serum for 24 hours developed persistent HB8 antigenemia which was noticed as early as seven days after birth.
Effectiveness of genotype C-derived hepatitis B vaccine in preventing perinatal transmission in children born to hepatitis B virus carrier mothers infected with genotype A
