Jonas Salk worked on an influenza vaccine for the U.S Army during 1947. He was the director of research laboratory of University of Pittsburgh School of Medicine. He worked on a disease similar to Polio. Jonas Salk had been testing the vaccine for 2 years for Polio.The vaccine was made to contain Polio. Polio made people paralyzed because Polio got to the central nervous system and spreaded so quickly that the cells were already damaged. Jonas Salk was not the only one who was working on a vaccine for Polio. Another scientist who was making a vaccine different than Salk's vaccine was Dr.Albert Sabin.