Political, social and technical risks in the last stages of disease eradication campaigns.

Eradication of a disease is one of the greatest gifts any generation can give to subsequent ones, but most attempts have failed. The biggest challenges occur in the final stages of eradication and elimination campaigns. These include falling public support as a disease becomes less common; the emergence of groups who do not support eradication; spiralling costs; and the evolution of drug, vaccine or insecticide resistance. Mass campaigns become less effective as the disease fragments and modelling becomes less reliable. Optimism bias is the biggest risk to any eradication campaign and the long endgame must be planned for from the beginning.