Viruses, Serums, Toxins, and Analogous Products; Rabies Vaccine, Killed Virus and Rabies Vaccine, Live Virus

We are amending the standard requirements for establishing the immunogenicity of Rabies Vaccine, Killed Virus and Rabies Vaccine, Live Virus. The amendment changes and clarifies alternate test procedures which may be used in animals other than carnivores. Under the rule, when a reduced number of challenge animals is used in a rabies immunogenicity test, all vaccinates must survive challenge. If one or more of the challenged vaccinates die of rabies, all of the remainder of the vaccinates will have to be challenged or the test will be deemed unsatisfactory and terminated. This action corrects a problem associated with rabies immunogenicity tests in the regulations and makes other changes deemed necessary for clarity and consistency.