STUDY ON THE COMPARATIVE IMMUNOGENICITY OF A RECOMBINANT-DNA HEPATITIS-B VACCINE CONTAINING PRE-S COMPONENTS OF THE HBV COAT PROTEIN WITH NON PRE-S CONTAINING VACCINES

A new recombinant hepatitis B vaccine (SCI-B-VAC), derived from Chinese hamster ovary (CHO) cells and consisting of both the major S protein and the minor pre-S-1 and pre-S-2 proteins of the viral coat were compared with two yeast-derived vaccines containing only S proteins (B-Hepavac II and Engerix-B) for immunogenicity in human volunteers in a randomized controlled study. Two hundred and ninety-five healthy subjects completed the 12 month follow up. There was no difference in the mean age and sex distribution among the three study groups. Seroconversion rates for all the three groups were similar at months 6, 9 and 12. However, hepatitis B surface antibody (anti-HBs) geometric mean titres (GMT) were significantly higher with 10 mu g SCI-B-VAC and 20 mu g Engerix-B than with 10 mu g B-Hepavac-II at months 6, 9 and 12. SCI-B-VAC at month 6 also showed a significantly higher anti-HBs GMT than Engerix-B (295 vs 143 miu/ml, P < 0.02).