Abstract

PIP: Poliomyelitis and measles, which cause much mortality and morbidity in developing countries, are at present considered the diseases for which conditions are most favorable to eradication. Such campaigns can gain impetus from the successful eradication of smallpox in 1977. Features of smallpox that facilitated eradication included: characteristic rash, identifiability of virus location, lack of subclinical cases, absence of an animal reservoir, no vector, seasonality, no latency, only 1 serotype, and a stable vaccine. A prerequisite for an effective eradication campaign is that the infection must be capable of being eliminated from localized areas or a single country. Poliomyelitis, measles, and yaws meet this criterion. Both inactivated and live attenuated polio vaccines have the potential for effective control of the transmission of the polio virus, but they have different modes of action and require different strategies. Because very high rates of immunization with either vaccine appear to be necessary to control the wild-type virus in tropical and subtropical areas, the oral live vaccine of Sabin is likely to prove most acceptable. The rates of vaccine acceptance reported to date from the World Health Organization's Expanded Program on Immunization (EPI) cannot be expected to yield the results required for control and mass administration seems to be indicated. Measles shares many of the features of smallpox that made eradication possible. As a result of efforts to immunize at least 95% of the population, the US is nearing elimination of measles virus. The use of diploid cells for making vaccine has enabled the virus to be given as an aerosol to infants under 6 months of age. Again, in many countries seeking to routinely immunize infants under the EPI, vaccine acceptance rates are too low and technical modifications appear called for. Revival of the former yaws campaign is under debate. Unless dramatic steps are taken to control infection, health in developing countries will continue to be undermined.