Antibody response after a two-year intradermal booster of rabies human diploid cell vaccine

A study was undertaken to evaluate the effectiveness of a low dose of rabies human diploid cell vaccine administered intradermally for preexposure booster inoculation. Seventy-six volunteers received a 0.1-ml dose of rabies human diploid cell vaccine intradermally, approximately 2 years after their primary series. Though only 25 (32.9%) had a titer less than 0.5 IU/ml before the booster, all had a postbooster titer of greater than or equal to 4.0 IU/ml 3 weeks later. Five of 73 (6.8%) reported an allergic reaction after the booster.