we have for all intents and purposes eradicated polio in the areas that trust vaccines. it's in basically 2 places now because of a few factors but a large one is that the taliban doesn't trust them and think it's a sterilizing campaign... pakistan, and afganistan.
Don't get it twisted: the CIA disguised its spies as polio vaccine administrators[1]. We could have eradicated the virus had the medical staff not been weaponized.
There have been both blunt and sharp political forces in play. As far as I know, CIA never operated this way in northern Nigeria, yet that was one of the anti-vax hold-outs where polio was kept alive.