For anyone interested in why polio hasn't been eradicated, it is likely related to the capture of Osama Bin Laden.
https://www.theguardian.com/world/2011/jul/11/cia-fake-vacci...
https://www.theguardian.com/world/2011/jul/11/cia-fake-vacci...
[1] http://www.endpolio.com.pk/polio-cases-district-wise-2016