Prior to the availability of the vaccine, summers(the time when polio was most likely to strike a victim) were a time of anxiety for parents, since little Johnny or Mary could be in perfect health today and dead in a two or three days. I personally know a person who lost a playmate in his childhood quite abruptly.
But even adults were at risk, since there was no way to know if you had been exposed to the virus and been rendered immune, or simply been lucky in your childhood and never exposed to the virus. Franklin Roosevelt was almost forty when he came down with polio.
Let me take the opportunity of this post to warn all its readers to make sure loved ones are vaccinated.