Role of hepatitis B immunoglobulin in infants born to hepatitis B e antigen-negative carrier mothers in Taiwan

Background. The efficacy of hepatitis B immunoglobulin (HBIG) in infants of hepatitis B e antigen (HBeAg)-negative hepatitis B surface antigen (HBsAg) carrier mothers in Taiwan is not clear. Objective. To describe the responses of infants born to HBeAg-negative carrier mothers receiving HBIG combined with hepatitis B vaccine. Methods. Term babies born to HBeAg-negative carrier mothers were assigned based on chart number to 1 of the 2 treatment groups. Group A infants (n = 94) received 0.5 ml (145 IU) of HBIG within 24 h of birth and 3 subsequent doses of recombinant hepatitis B virus (HBV) vaccine at 3 to 5 days, 1 month and 6 months of age. Group B infants (n = 122) received 3 doses of vaccines only. Infants (n = 19) born to HBeAg-positive. carrier mothers were treated like those in Group A and are referred to as Group C. Sera obtained from infants at 2 and 7 months of age were tested for hepatitis B virus (HBV) markers. Results. There were 2 (1%; one in Group A and one in Group B) subclinical breakthrough hepatitis B infections among studied infants. One (5%) child of Group C had asymptomatic HBV infection at the age of 7 months and became a chronic carrier. The rate of protective anti-hepatitis B surface antibody (anti-HBs) titers achieved (>10 mIU/ml) by 2 months of age was significantly higher in Group A than that in Group B (98% vs. 57%, P < 0.001). However, it was not different by 7 months of age. Infants (Group A) immunized with HBIG and vaccine had a significantly higher geometric mean titer (GMT, milli-International Units/ml) of anti-HBs than those (Group B) with vaccines only at 2 months of age (P < 0.001). Conversely at 7 months of age, the GMT of anti-HBs was significantly higher in infants who received vaccine only (P = 0.001). Conclusions. A protective level of antibodies was achieved earlier in those infants receiving both passive and active immunizations. However, infants receiving active immunizations alone achieved a higher GMT at 7 months of age. There was no clear benefit of passive-active vs. active immunization alone for chronic HBV infection in infants of HBsAg-positive, HBeAg-negative mothers.