World Leaders Make Final Push to Eradicate Polio

Polio has now disappeared from almost every corner of the world. Even India, once viewed as the country with the most intractable polio problem, has been free of new cases for more than 18 months. But the disease still lingers in three countries, and world leaders convened by the United Nations last week vowed to make a final, all-out push to rid the planet of polio.