At its peak in the 1940s and 1950s, polio was killing or paralyzing more than a half-million people worldwide each year, especially children and young adults. The “lucky” survived to walk on crutches. Others were so paralyzed they could no longer breathe on their own. Iron lungs, the mechanical ventilators that sustained them, symbolized polio’s reign of terror.
In 1947, the University of Pittsburgh recruited Jonas Salk—an expert in influenza whose flu vaccine is still in use today—to develop a virus program at Pitt. For more than seven years, his team worked tirelessly to develop an effective killed-virus vaccine.
The efforts of Pitt's polio research team culminated in the largest national controlled field trial in history. At the trial’s successful conclusion, the federal government approved the vaccine for the public on April 12, 1955, an action that Newsweek called “a summit moment in history.”
from:: Pitt’s Historic Impact