According to Time, the Taliban are the only thing in the way of eradicating polio. So I will digress from economics here because I just can’t stand it.
Excuse me? For god’s sake – in the USA we can’t get nice college educated housewives to vaccinate their children. And we blame the Taliban for becoming anti-vaccination?
The CIA used vaccine work as cover to get Osama bin Laden. Then every detail of that mission got trumpeted across the world. That is what caused the Taliban’s blowback campaign against vaccination workers. Who can blame a bunch of uneducated hillbillies for becoming suspicious of all vaccination campaigns? Our drones rain fire from the sky and they can’t see them. A new generation has grown up since 9-11 who know little except that. We have not exactly tamed our own hillbillies with guns, now have we?
Re-ignition of polio by mutation of attenuated vaccine strains into virulent forms is another major problem. This is why Nigeria was almost eradicated and is no longer.
Then there is dealing with the small fraction of people who develop chronic infection and shed virus for years. That takes decades of public health which means sanitation and vaccination.