Polio is a disease that can paralyze muscles and can cause death. The cause of polio was not known but people believed that the disease was associated with swimming pools and unsanitary conditions. Scientists did not discover that polio was caused by a virus until the 1930's. We now know that polio is most often spread by direct contact between people.
Paralysis occurs when nerves to the muscles become infected with poliovirus.
Basic and clinical research provided the knowledge that led to the development of the Salk polio vaccine in 1954. In 1957 Dr. Sabin introduced an oral polio vaccine that was made from live poliovirus that had been attenuated so that it could not produce the disease. Both of these vaccines were possible only because another researcher, Dr. Enders, discovered how to grow large amounts of poliovirus in monkey kidney tissue culture. The prevention of polio is one of many examples of how scientists conduct biomedical research to learn how to prevent and treat human and animal diseases.