Immunogenicity of intradermal vaccination of Japanese rabies vaccine for preexposure immunization following WHO recommendation.

In the present study, we evaluated the immunogenicity of intradermal vaccination of Japanese purified chick embryo cell rabies vaccine (PCEC-K) for preexposure immunization (PEI). A total of 39 healthy subjects were administered a single 0.1-ml dose of PCEC-K intradermally at the antebrachial region on days 0, 7, and 28. To assess immunogenicity, rabies neutralizing antibody (NA) titers were measured on days 7, 28, and 42 post vaccination. By day 42, all subjects developed NA titers ≥0.5 IU/ml (geometric mean titer, 2.7 IU/ml), a level that is considered protective. The vaccine was well tolerated; vaccinated subjects displayed minimal redness and pruritus. Although a 1.0-ml dose of PCEC-K administered subcutaneously is considered the standard method, the intradermal regimen using a 0.1-ml dose of PCEC-K is immunogenic, safe, and highly recommended for situations of vaccine shortage.