Immunogenicity of 20 micrograms of recombinant DNA hepatitis B vaccine in healthy neonates: a comparison of three different vaccination schemes.

The immunogenicity of a full dose (20 micrograms) of recombinant DNA yeast-derived hepatitis B vaccine (Engerix-B) was assessed in healthy neonates in order to compare three candidate vaccination schemes. After randomization 162 newborns of hepatitis B surface antigen (HBsAg) negative mothers entered the study. Neonates received hepatitis B vaccine according to a four-dose vaccination scheme starting either at month 3 (scheme 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 according 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 vaccinated newborns suffered mild transient local symptoms. The vaccine was highly immunogenic irrespective of vaccination scheme; all infants developed anti-HBs levels > or = 10 IU/L, 97% > or = 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 the three-dose scheme started at birth. Hepatitis B vaccination according to the four-dose scheme started at month 3 produced significantly higher (P < 0.05) antibody levels in comparison to the four-dose scheme started directly after birth. This study showed that a four-dose hepatitis B vaccination scheme starting at month 3 resulted in the highest antibody levels of the three schemes investigated and can be recommended for incorporation in the Expanded Programme on Immunization in The Netherlands.