Global withdrawal of serotype-2 oral poliovirus vaccine (OPV2) took place in April 2016. This marked a milestone in global polio eradication and was a public health intervention of unprecedented scale, affecting 155 countries. Achieving high levels of serotype-2 population immunity before OPV2 withdrawal was critical to avoid subsequent outbreaks of serotype-2 vaccine-derived polioviruses (VDPV2s).

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In 1988, the World Health Assembly (WHA) passed a historic resolution to eradicate polio by the year 2000, resulting in the creation of the largest public–private partnership for health—the Global Polio Eradication Initiative (GPEI). When GPEI was launched, wild polio virus (WPV) was endemic in 125 countries and resulted annually in the paralysis of more than 350,000 people, mainly children. By 2000, the number of endemic countries had been reduced to 20, with the last WPV type 2 case occurring in 1999.