Stopping poliovirus vaccination after eradication: issues and challenges

Since 1988 reported polio cases worldwide have declined by about 85% and the number of known or suspected polioendemic countries has decreased from over 120 to less than 50. With eradication of poliomyelitis approaching, issues potentially affecting when and how vaccination against poliovirus can be stopped become extremely important. Because of the potential risks and benefits inherent in such a decision, the best available science, a risk-benefit analysis, contingency plans, a stock pile of poliovirus vaccines, and the endorsement by the global policy-making committees will all be needed before vaccination can be discontinued. The scientific basis for stopping polio immunization has been reviewed by WHO. This Round Table article summarizes the current state of knowledge, provides an update on the processes and timelines for certification, containment, and stopping vaccination, and highlights some of the unanswered scientific questions that will be addressed by further research. These include whether transmission of vaccine-derived poliovirus strains could be sustained so that poliomyelitis could re-emerge in a future unvaccinated population and whether prolonged excretion of vaccine-derived poliovirus from individuals with immune deficiencies could be a mechanism through which this could occur

A TALE OF TWO GLOBAL HEALTH PROGRAMS Smallpox Eradication's Lessons for the Antipolio Campaign in India

India provided one of the most challenging chapters of the worldwide smallpox eradication program. The campaign was converted from a project in which a handful of officials tried to impose their ideas on a complex health bureaucracy to one in which its components were constantly adapted to the requirements of a variety of social, political, and economic contexts. This change, achieved mainly through the active participation of workers drawn from local communities in the 1970s, proved to be a momentous policy adaptation that contributed to certification of smallpox eradication in 1980. However, this lesson appears to have been largely forgotten by those currently managing the Global Polio Eradication Initiative. We hope to show ways in which contemporary efforts to eliminate polio worldwide might profitably draw on historical information, which can indicate meaningful ways in which institutional adaptability is likely to help counter the political and social challenges being encountered in India