Poliomyelitis (polio) is a highly contagious viral disease that primarily affects children under the age of five. The virus multiplies in the colon before entering the neurological system and causing paralysis. It spreads from person to person primarily by the faecal-oral pathway and less frequently by a common vehicle (such as contaminated water or food).

The Global Polio Eradication Initiative, led by national governments, WHO, Rotary International, the US Centers for Disease Control and Prevention (CDC), UNICEF, and later joined by the Bill & Melinda Gates Foundation and Gavi, the Vaccine Alliance, was established in 1988 after the World Health Assembly adopted a resolution calling for the eradication of polio worldwide.