@Type_Other @RedpillBot Scalar used to post about this.
The rise and fall of Polio is directly linked to human activity separate from vaccine development. What the Polio vaccine did was immunize people against a virus that had already been dealt with.

x.com/forrestmaready/status/1005127713848463361?t=PGJr9H71f982p-CgqexfZg&s=19

Additionally, the majority of new Polio cases in the current day are from strains descended from vaccine strains as opposed to wild strains - again man has made the problem worse.