A rare photograph of American President Franklin D. Roosevelt in a wheelchair, a paralyzed victim of polio from 1921 until his death in 1945 (c. 1941)

16. Despite almost total eradication by the end of the 20th century, polio has reemerged in troubled regions of the planet where vaccination efforts have stalled due to conflict and civil unrest

Poliomyelitis, commonly known as polio, is an infectious disease that results in muscle fatigue and weakness. In the most extreme cases, polio renders infected individuals paralyzed, as in the case of Franklin Roosevelt, whilst historically between 15 and 30 percent of adults who contracted the disease ultimately being killed. Plaguing humanity throughout history, with references to the illness present in ancient Egyptian paintings, polio was not properly identified by physicians until the late-18th century. Exploding during the 20th century, polio epidemics began in both Europe and the United States. In 1952 there were 58,000 reported new cases; of these, at least 3,145 proved fatal and 21,269 victims were left paralyzed.

In the wake of these pandemics, grassroots fundraising campaigns began to emerge to finance revolutionary treatments to combat polio. Successful in their objective, by the late-1950s and 1960s a vaccine against polio had been invented, whilst methods of treatment were vastly improved. However, despite the Global Polio Eradication Initiative inoculating more than 2.5 billion children since 1988, polio has in recent years began to rear its head once more. In states undergoing persistent turmoil, notably Afghanistan, Pakistan, Nigeria, and Ukraine, new cases of polio have been reported in the 2010s and without widespread and sustained vaccination efforts might spread even further.