1.   As the years went on and no better idea about how one got polio was advanced, the theory took on importance.

2.   The risk of getting polio from the vaccine is much lower than otherwise.

3.   If someone got polio, people would move out of the neighborhood.

4.   Their mothers worried that they would get polio.

5.   Religious communities that refuse immunizations got polio and spread it to IPV recipients.