Nothing demonstrates human interconnectedness like the spread of infectious disease. Polio is endemic to just three countries: Afghanistan, Nigeria and Pakistan. In recent years however, visitors have carried polio back to 39 previously polio-free states. Thus people everywhere have a stake in eradicating polio, as we have stamped out smallpox.
Immunizing the last unvaccinated children on the planet is an expensive and complex undertaking, and worth it in the long run. The world not only would be forever spared an incurable, crippling and often fatal disease. It would also save a lot of money. If polio transmission could be stopped by 2015, the net benefit from reduced treatment costs and productivity gains through 2035 would be $40 billion to $50 billion, according to a 2010 study.
Thanks to the efforts of the Global Polio Eradication Initiative — which links national governments to the World Health Organization, the U.S. Centers for Disease Control and Prevention, Unicef, Rotary International and the Bill & Melinda Gates Foundation — progress has been tremendous.
The coalition has adopted an emergency plan that prioritizes efforts in the three endemic countries. (Remarkably, India, which because of population density and poor sanitation was considered the greatest challenge, had zero new polio cases last year.) The idea is to stop the virus at the source and hope it doesn’t spread to places where vigilance has been lightened.