Eradication in the Americas Economically Justified ?

Since the eradication of smallpox in the 197Os, no other disease has been eliminated from the world by vaccination. Advances in mass immunization campaigns using oral vaccine have successfully interrupted the transmission of wild poliomyelitis virus in many countries, however, and have sharply reduced its incidence in many others (1, 2). The benefits of polio immunization appear from some studies to outweigh its costs (3), and the cost-effectiveness of mass campaigns relative to other means of reaching the susceptible population has been established, at least in some circumstances (4). It therefore seems possible, by a suitable intensification of such efforts, to eradicate polio-if not all over the world, then at least in the Western Hemisphere-within the next few years. In view of the success of the PAHOlWHO Expanded Program on Immunization (EPI) in the Americas since its inception in 1977, in April 1985 (5) PAHO recommended that its Member Governments support a five-year, US $46 million campaign to eliminate polio entirely from the Americas, after having to treat or rehabilitate polio viea