National immunization days: experience in Latin America.

Organization of national immunization days (NIDs) in all countries in Latin America in which polio was endemic has been one of the key elements that led to the interruption of the circulation of the wild poliovirus in 1991 from the Americas. National initiatives for control or elimination of measles using similar strategies have emerged from the successful organization of NIDs for polio eradication and lead the way to the eventual global eradication of this major killer of children. The major reasons for the success of polio eradication in the Americas were the commitment of national authorities, well-defined strategies, sustainable effort, and the participation of all sectors of society.