Comparative trial of low-dose, intradermal, recombinant- and plasma-derived hepatitis B vaccines.

The immunogenicity and reactogenicity of low-dose, recombinant DNA and plasma-derived hepatitis B vaccines were investigated in a prospective, double-blind, randomized, controlled trial. Volunteers (153) received either recombinant vaccine, 10 micrograms in 1 ml intramuscularly; plasma-derived vaccine, 2 micrograms in 0.1 ml intradermally or recombinant vaccine, 1 microgram in 0.1 ml intradermally at 0, 30, and 150 days. Peak geometric mean concentrations of antibody to hepatitis B surface antigen at day 200 were 1094, 387, and 43 mIU/ml, respectively. By day 360, these concentrations had fallen to 346, 124, and 19 mIU/ml, respectively (P less than .05 between groups both dates). Number of subjects with antibody greater than or equal to 10 mIU/ml at day 200 was similar between the 10-micrograms recombinant and 2-micrograms plasma-derived groups (94% vs. 90%), while only 78% of the 1-microgram recombinant group had protective concentrations of antibodies (P less than .05). Erythema and induration occurred in most subjects in both intradermal groups, while pain was prominent at the intramuscular site especially after the second dose. Thus, plasma-derived vaccine, 2 micrograms in 0.1 ml intradermally, appears to be an acceptable cost-saving method for hepatitis B immunization, while recombinant-derived vaccine, 1 microgram in 0.1 ml intradermally, produced less satisfactory results.