Prolonging morbidity in rabid dogs by intrathecal injection of attenuated rabies vaccine.

Dogs vaccinated intrathecally with attenuated rabies vaccine developed antibodies that were detected in the cerebrospinal fluid, blood, and brain; dogs similarly vaccinated but with an inactivated vaccine developed no antibodies in the brain. When the attenuated vaccine was administered to rabid dogs, a prolongation of the morbidity period was noted and, in some dogs, recovery from the disease. Rhesus monkeys died when administered any of the available attenuated vaccines intrathecally, and further studies with that species could not be undertaken.