ABSTRACT
In the 1870s, Louis Pasteur further developed the concept that a weakened form of an organism maintained antigenicity without infectivity and therefore provided immunity without causing disease. The concept was put to the test with the production of a successful vaccine to protect against chicken cholera. Using the same principles, Pasteur then developed a successful vaccine for sheep anthrax before turning his attention to rabies, vaccine, the first vaccine manufactured in the laboratory and used in humans. The transmissible agent of rabies was unknown but believed to be transferred in the saliva of dogs. It was called a ‘‘virus,’’ a generic term for nonbacterial infectious agents. Pasteur recreated the disease in rabbits by direct cerebral inoculation of infected material. The spinal cords were later removed and dried for varying lengths of time to make vaccines of varying infectivity. Rabbits were immunized with a series of increasingly potent vaccines and were then
protected when challenged with an intracerebral inoculation of freshly infected material. The vaccine was grown on the spinal cord of mature animals and contained myelin basic protein.
