HBIG immunoprophylaxis of babies born to HBsAg carrier mothers.

Screening of 12 965 pregnant women revealed a prevalence of HBsAg carriers of 3.5%. Of these 4.8% were positive for HBeAg, 92.1% for anti-HBe and 3.1% were HBeAg/anti-HBe negative. Babies born to HBeAg positive mothers were found to be at extremely high risk of acquiring HBV infection and of developing a chronic carrier state, while those born to anti-HBe positive mothers were at lower yet consistent risk of infection and none of them became chronic carriers. Starting from October 1980 babies born to HBsAg carrier mothers were submitted to HBIG treatment. Babies born to anti-HBe mothers received two 0.2 ml/kg doses i.m. at birth and at one month of age, while babies born to HBeAg positive mothers were injected again at 3 and 6 months. After a prolonged follow-up it emerged that: 1) HBIG treatment was of some efficacy in preventing HBsAg chronic carrier state following perinatal transmission of HBV; 2) HBIG treatment rather than preventing HBV infection delayed its onset; 3) interruption of transmission of HBV may also be useful in preventing delta infection since this can occur only in circumstances that permit transmission of HBV infection.