The World Health Organization and other groups have failed to eradicate polio, the waterborne paralytic disease that mostly strikes children under age 5, despite a $1 billion investment and several years of work, news sources are reporting.  According to The Associated Press, the disease is still active in a number of countries, including Afghanistan, Angola, Chad, India, Pakistan and Nigeria.

There is an effective polio vaccine, discovered by Jonas Salk in 1952, but it has not been given consistently to children in those countries, and in some cases has reportedly been disrupted by political corruption, incorrectly administered vaccines, and falsified immunization reports.

In the 1940s and 50s, polio was a common and dreaded childhood disease in the United States, affecting an estimated 35,000 people.  According to the Centers for Disease Control and Prevention, the last naturally occurring case of polio in the United States was in 1979, though a handful of cases have occurred since then, mostly contracted as a side effect of an oral polio vaccine that is not routinely used by pediatricians today.