Reduced doses of hepatitis B immune globulin in the prevention of perinatal transmission of hepatitis B

From October 1982 to May 1983, newborn infants of 79 hepatitis B surface antigen (HBsAg)‐positive women were enrolled in a study of the efficacy of hepatitis B immune globulin (HBIG) in the prophylaxis of perinatal transmission of hepatitis B virus (HBV) infection. HBIG 0.5 ml or 0.25 ml was given to the newborn within 15 minutes of birth and at 3 and 6 months. The mother‐infant pairs were followed‐up every 3 months for at least 9 months. Similar observations of untreated infants were used for comparison. Among infants of hepatitis B e antigen (HBeAg)‐positive carrier mothers, the HBsAg carrier rates at 3 months were similar in the 0.5‐ml and 0.25‐ml HBIG dose groups. At 12 months the difference—17.7% of 17,40% of 15—did not reach statistical significance, but the differences between these rates and that of the untreated control—85.7% of 35—did. Among infants of HBeAg‐negative carrier mothers, HBV infection rates in both dose groups were similar to those of untreated infants. In the treated groups at 12 months about 45% of infants of HBeAg‐positive mothers and 90% of infants of HBeAg‐negative mothers were still negative for HBsAg and anti‐HBs. Vaccination to induce active antibody is necessary to prevent postnatal infection and chronic carriage of HBV. To reduce the cost of combined passive and active hepatitis B immunoprophylaxis in children born to HBeAg‐positive carrier mothers, 0.25 ml of HBIG could be used instead of the usually recommended 0.5 ml.