Background: Worldwide eradication of wild polioviruses is likely to yield substantial health and financial benefits, provided we finish the job. Challenges in the four endemic areas combined with continuing demands for financial resources for eradication have led some to question the goal of eradication and to suggest switching to a policy of control.
Methods: We developed a dynamic model, based on modelling of the currently endemic areas in India, to show the importance of maintaining and increasing the immunisation intensity to complete eradication and to illustrate how policies based on perception about high short-term costs or cost-effectiveness ratios without consideration of long-term benefits could undermine any eradication effort. An extended model assesses the economic implications and disease burden of a change in policy from eradication to control.
Findings: Our results suggest that the intensity of immunisation must be increased to achieve eradication, and that even small decreases in intensity could lead to large outbreaks. This finding implies the need to pay even higher short-run costs than are currently being spent, which will further exacerbate concerns about continued investment in interventions with high perceived cost-effectiveness ratios. We show that a wavering commitment leads to a failure to eradicate, greater cumulative costs, and a much larger number of cases. We further show that as long as it is technically achievable, eradication offers both lower cumulative costs and cases than control, even with the costs of achieving eradication exceeding several billion dollars more. A low-cost control policy that relies only on routine immunisation for 20 years with discounted costs of more than $3500 million could lead to roughly 200 000 expected paralytic poliomyelitis cases every year in low-income countries, whereas a low-case control policy that keeps the number of cases at about 1500 per year could cost around $10 000 million discounted over the 20 years.
Interpretation: Focusing on the large costs for poliomyelitis eradication, without assessing the even larger potential benefits of eradication and the enormous long-term costs of effective control, might inappropriately affect commitments to the goal of eradication, and thus debate should include careful consideration of the options.