Identifying the Polio Virus

By the early 1900s scientists knew that polio was contagious but had not yet identified the microbial agent that caused the disease. In 1908 Austrian pathologist Karl Landsteiner first isolated and identified poliovirus from the spinal fluid of a young polio victim.

At the same time, American pathologist Simon Flexner confirmed the viral origins of polio. He also developed useful means of growing the poliovirus for experimental purposes in laboratory animals. Once polio was recognized as a viral disease, scientists focused on developing a vaccine to prevent the disease.