I had a friend in the 60s, a little girl, whose parents didn’t vaccinate her for polio. Yup, you guessed it. She came down with it. Something like 27 operations on her legs - they were absolutely mutiliated and her entire childhood was spent in casts. I do believe polio can return later in life...
I didn’t say there shouldn’t have been a polio vaccine. There shouldn’t have been a polio vaccine that contained live monkey viruses.