Albert Bruce Sabin (August 26, 1906 - March 3, 1993) was an American medical researcher best known for having developed an oral polio vaccine. The Sabin vaccine consists of weakened forms of the viruses that cause polio. It protects the body against polio without causing the disease. The Sabin vaccine is easier to give than the earlier vaccine, developed by Jonas E. Salk in 1954, and its effects last longer. In addition, those who received the Salk vaccine could pass on the polio virus. During World War II he was a lieutenant colonel in the US Army Medical Corps and helped develop a vaccine against Japanese encephalitis. In 1983, Sabin developed calcification of the cervical spine, which caused paralysis and intense pain. This condition was successfully treated by surgery conducted at Johns Hopkins Hospital in 1992 when Sabin was 86. A year later Sabin died from heart failure.