[overtone1000]

It's more accurate to say the wild poliovirus eradication effort has been stagnant in Afghanistan and Pakistan for over a decade.

[BLKNSLVR]

And relatively recently there were a fair few US citizens rotating in and out of Afghanistan.

[giantg2]

And they received vaccines appropriate for their deployment. Similar to Yellow Fever - not required in the US, but required related to travel to/from risky areas.