COMPARATIVE-STUDY OF THE IMMUNOGENICITY AND SAFETY OF 2 DOSING SCHEDULES OF ENGERIX-B(R) HEPATITIS-B VACCINE IN NEONATES

A randomized multicenter study compared the routine hepatitis B vaccin e schedule of 0, 1, 6 months with an accelerated schedule of 0, 1, 2 m onths in newborns. Two hundred ninety-nine infants whose mothers were seronegative for hepatitis B were enrolled in the study and randomized to either the routine or accelerated schedule. All infants had blood drawn for antibody titers to hepatitis B at 2, 3, B and 7 months of ag e. For 222 infants data were evaluable, at least for safety; 193 of th ese 222 had antibody titers that were evaluable. The infants vaccinate d on the accelerated schedule developed seroprotective concentrations of antibody more quickly than the infants vaccinated on the routine sc hedule; 92.6% vs. 66.1% had seroprotective concentrations (equal to or greater than 10 mIU/ml) at 3 months of age (P < 0.001). However, infa nts in the accelerated schedule had lower geometric mean antibody tite rs at 7 months, 420.0 vs. 3141.8. We conclude that the accelerated vac cination schedule resulted in the more rapid development of seroprotec tive concentrations of antibody, but levels of antibodies were not as high as in the routinely vaccinated infants at 7 months. These data su ggest that an accelerated vaccine schedule can be used in the newborn period. The effectiveness of the accelerated schedule in preventing pe rinatal infections compared to the standard schedule and the necessity for booster doses of vaccine remain to be studied.