On Feb. 23, 1954, the first mass inoculation of the new Polio vaccine, developed by Dr. Jonas Salk at the University of Pittsburgh, was initiated. The vaccination began with students of Arsenal Elementary School, the first of the more than 5,000 6- to 9-year-olds from 19 City of Pittsburgh schools to receive the experimental vaccine.

The clinical trials of the Salk vaccine were the largest ever conducted, involving nearly two million children. Though one bad batch of the vaccine from Cutter Labs had killed 10 people and gave 200 others polio, in April 1955, Dr. Thomas Francis Jr. of the University of Michigan announced that the vaccine was found to be 90 percent effective and that it was “safe, effective and potent.”