Clinical evaluation of low-dose intradermally administered hepatitis B virus vaccine. A cost reduction strategy.

High cost and limited availability of the current hepatitis B virus vaccine lead to underutilization. To address this problem, we performed a vaccine trial comparing the currently recommended regimen of 20 micrograms of hepatitis B surface antigen (HBsAg) intramuscularly on days 0, 30, and 180, with a more economical regimen of 2 micrograms of HBsAg intradermally on days 0, 30, and 180. This trial was performed in 50 seronegative health care workers to assess the immunogenicity and local reactogenicity of both vaccine regimens. We found no significant difference in seroconversion between the intradermal group (96%) and the intramuscular group (100%). Mean ratios of test sample value to mean negative control value for antibody to HBsAg at 360 days were not significantly different (intradermal group, 84 +/- 26; intramuscular group, 120 +/- 22). Reactions in both groups were minor. Although the optimal dose of HBsAg was not investigated, our data demonstrate that 0.1 mL of inactivated hepatitis B virus vaccine (Heptavax-B) intradermally is immunogenic in healthy adults. Vaccination by this regimen can broaden hepatitis B virus disease prevention.