To the Editor.—
Because the antibody response following the recommended preexposure or postexposure vaccination regimen with rabies vaccines licensed for human beings in the United States, ie, human diploid cell rabies vaccine (HDCV) and rabies vaccine adsorbed (RVA), has been so satisfactory, routine postvaccination testing to document seroconversion is not necessary.1,2Serologic testing continues to be recommended if a problem or irregularity related to rabies vaccine or the host response is suspected; in such cases, the Centers for Disease Control (Atlanta, Ga) offers serologic testing on an individual case basis. The Centers for Disease Control also maintains a surveillance system in Georgia and Illinois; physicians in these states are asked to submit serum specimens following all preexposure and postexposure courses. In addition, the Veterinary Diagnostic Laboratory of Kansas State University (Manhattan) performs serologic testing on a fee-for-service basis for anyone in the country requesting testing.From 1985 through 1988,