Reliability of the rabbit pyrogen test and of the limulus test in predicting the pyrogenicity of vaccines in man.

Commercial vaccines including bacterial as well as live and inactivated viral vaccines were examined in the rabbit pyrogen test and in the limulus test. The laboratory results were compared with the reactivity in humans. A fairly good correlation was found between the temperature rise in rabbits and the frequency of febrile reaction in the vaccinees. Two rabies vaccines and a tick-borne encephalitis virus vaccine, each pyrogenic both in rabbit and in man. were negative in the limulus test. The pyrogenicity of these vaccines is attributed to the vaccine virus itself.