Up until 1955, polio was still a definite threat to the health of every individual in the world. In 1952, there were 58,000 cases of polio in the United States, the worst year ever. In 1953, there were 35,000 cases of polio in the U.S.A. People would panic when an outbreak of polio occurred. Because it was passed by human to human contact, when an outbreak occurred people would stay away from crowded areas. I can remember periods where my Mother wouldn't allow me to go out to play because of the possibility of catching polio.
The Salk vaccine was developed in 1952 and by 1954, massive field trials began sponsored by the National Foundation for Infantile Paralysis. The trials were so successful that in April, 1955, the vaccine began being distributed to the public. By 1957 there were only 5600 cases of polio in the United States.
Suddenly, we were allowed to go in public no matter what the weather or how many people were in a crowd. I had never been allowed to run through muddy water, now it was okay. We went to the beach more often, the park and other crowded events. Life became more relaxed.