The global eradication of poliomyelitis: progress and problems.

Encouraged by the success of the global smallpox eradication certified in 1980, the global poliomyelitis eradication program was launched in 1988 by the World Health Organization (WHO). In addition to routine polio immunization included in the Expanded Program of Immunization (EPI), two major activities were planned: mass polio vaccination campaigns and surveillance of all cases of acute flaccid paralysis. In 2000, the disease had been eliminated from most countries in the world. However, as of 2002, the community acceptance of vaccination was endangered in some countries by rumors about assumed adverse effects of oral polio vaccine. The rejection of polio immunization provided a worrying resurgence of polio in Northern Nigeria, followed by re-infection of 21 countries, whereas resurgence of the disease also was observed in Northern India. Supplementary vaccination activities were resumed, additional resources were mobilized and, in 2007, most re-infected countries became polio-free again. Today, polio remains endemic in only four countries. The goal of global polio eradication has now been set at 2010, but doubts have been expressed about the feasibility of its achievement.