Before the development of the inactivated poliovirus vaccine (IPV) in 1955, poliomyelitis paralysed and killed up to half a million people every year. The introduction of the IPV in the USA led to a dramatic reduction in poliomyelitis transmission and cases, from an average 20000 cases per year in the 1950s to less than 1000 cases by the 1960s. With the development of the oral poliovirus vaccine (OPV) and the strategy to give two doses of trivalent OPV to all children younger than 5 years in mass vaccination campaigns, transmission was stopped in the USA by 1979. Similar campaigns were launched in many developing countries, notably in Latin America, following an initiative by the Pan American Health Organization to eradicate poliomyelitis in the Americas by 1990. In 1988, the World Health Assembly (WHA), with support and funding from Rotary International, unanimously launched a global goal to eradicate poliomyelitis by 2000. Since then the achievements of the Global Poliomyelitis Eradication Initiative, one of the largest global public health programmes, have been remarkable. From a situation in which poliomyelitis was endemic in 125 countries on five continents, paralysing 350000 children annually, there has been a 99% decrease in the global incidence of the disease, with only 20 countries with endemic disease in 2000. One of the three serotypes of wild poliovirus (serotype 2) has been eradicated since 1999.
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