Chasing Down Polio
Polio is on the ropes. Thanks to vigorous vaccination efforts around the world, there are only three countries left where polio is endemic: Nigeria, Afghanistan and Pakistan. NPR looks at how these nations are fighting to wipe out the virus, once and for all.
Children in a Lahore slum after heavy rains. The slum has a large population of Pashtuns who came from Pakistan's lawless tribal regions; many carry the polio virus with them.
Polio is deadly, but so is what's required to stamp it out once and for all in Pakistan: facing down Islamist extremists. The virus thrives in Pakistan's lawless — and largely inaccessible — tribal regions. To stop polio's spread, health workers must be courageous, clever and relentless.