Cost effectiveness of intradermal vs. subcutaneous hepatitis B vaccination for the mentally handicapped.

The currently available hepatitis B vaccine is being under utilized for reasons of cost and availability. To address this problem, we performed a recombinant hepatitis B vaccine trial comparing the currently recommended regimen of 10 micrograms subcutaneously (sc) in months 0, 1 and 6 with a more economical regimen of 2 micrograms intradermally (ID) in months 0, 1, 6. This trial assessed the immunogenicity of both regimens in 95 seronegative mentally handicapped patients. Forty four patients (aged 19-55 years, mean age 29.1 years) were vaccinated subcutaneously with recombinant vaccine and 51 (aged 19-52 years, mean age 28.3 years) were given intradermally. We found no significant difference in seroconversion between the subcutaneous group (93.2%) and the intradermal group (96.1%) 12 months after the first vaccination, but the antibody titres were lower in the intradermal group. We feel therefore that the dose should be increased slightly or further injections should be given. As the cost of intradermal vaccination is considerably lower than when using the subcutaneous route, underprivileged patients in institutions could the more readily be immunized against hepatitis B infection.