IMMUNOGENICITY OF 20-MU-G OF RECOMBINANT-DNA HEPATITIS-B VACCINE IN HEALTHY NEONATES - A COMPARISON OF 3 DIFFERENT VACCINATION SCHEMES

The immunogenicity of a full dose (20 mug) of recombinant DNA yeast-de rived hepatitis B vaccine (Engerix-B) was assessed in healthy neonates in order to compare three candidate vaccination schemes. After random ization 162 newborns of hepatitis B surface antigen (HBsAg) negative m others entered the study. Neonates received hepatitis B vaccine accord ing to a four-dose vaccination scheme starting either at month 3 (sche me I: months 3, 4, 5, and 11) or at birth (scheme III: months 0, 1, 2, and 11). Another group of neonates received hepatitis B vaccine accor ding to a three-dose scheme starting at birth (scheme II: months 0, 1, and 6). Serious adverse reactions were not observed; 2.5% of the vacc inated newborns suffered mild transient local symptoms. The vaccine wa s highly immunogenic irrespective of vaccination scheme; all infants d eveloped anti-HBs levels greater-than-or-equal-to 10 IU/L, 97% greater -than-or-equal-to 100 IU/L. The immunogenicity of hepatitis B vaccine after primary and booster vaccinations, administered in the four-dose scheme started at birth, was significantly higher (P < 0.05) than in t he three-dose scheme started at birth. Hepatitis B vaccination accordi ng to the four-dose scheme started at month 3 produced significantly h igher (P < 0.05) antibody levels in comparison to the four-dose scheme started directly after birth. This study showed that a four-dose hepa titis B vaccination scheme starting at month 3 resulted in the highest antibody levels of the three schemes investigated and can be recommen ded for incorporation in the Expanded Programme on Immunization in The Netherlands. (C) 1993 Wiley-Liss, Inc.