More Polio Cases Confirmed in Africa — Precision Vaccinations News
Polio - Our World in Data
Bill Gates - There were 350,000 new polio cases in 1988. Last year, there were 37. This is why I spent more time last year on polio than anything else: http://b-gat.es/2leNHPV
Two Stories of Disease: Smallpox and Polio | Earth Policy Institute