In May 1985, the Pan American Health Organization launched an initiative to interrupt indigenous transmission of the wild poliovirus from the Western Hemisphere by the year 1990. The strategy to achieve this goal was based on the maintenance of high levels of immunity in the population at risk and the establishment of a surveillance system to detect polio cases and respond promptly with control measures. On 23 August 1991, a 2-year-old boy with acute flaccid paralysis due to wild poliovirus was detected in Junin, Peru, the last isolation of such a virus in the entire Western Hemisphere. In 1990, an International Commission for the Certification of Eradication of Poliomyelitis Eradication (ICCPE) was established by the Pan American Health Organization to eventually determine if transmission was interrupted. After 3 years of follow-up and review of surveillance data, the ICCPE declared that wild poliovirus transmission had been interrupted in the Americas.