Immunogenicity of two different dosages (10 and 5 micrograms) of recombinant DNA hepatitis B vaccine in healthy neonates.

The immunogenicity of a half (5 micrograms) and a full (10 micrograms) dosage of recombinant DNA yeast-derived hepatitis B vaccine (HB-Vax-DNA) in healthy neonates was assessed in order to compare two candidate dosages of vaccine. After randomization 174 newborns of HBsAg-negative mothers entered the study. Neonates received four doses of either 10 or 5 micrograms hepatitis B vaccine, according to the DTP-polio immunization schedule at months 3, 4, 5 and 11. No serious adverse reactions were observed; 15.5% of vaccinated newborns suffered mild transient local symptoms. The vaccine was highly immunogenic irrespective of dosage of vaccine; all infants developed anti-HBs levels > or = 10 IU l-1, 99% > or = 100 IU l-1. A dosage of 10 micrograms hepatitis B vaccine produced higher antibody levels than 5 micrograms hepatitis B vaccine after primary vaccination (first three doses) but not after booster vaccination (fourth dose) (p = 0.06 and 0.75, respectively). Either vaccine dosage can be recommended for incorporation in the Expanded Programme on Immunization in the Netherlands.

RCT Entities:   Population Interventions Outcomes