Foot-and-mouth disease: the question of implementing vaccinal control during an epidemic.

The question of whether or not to use vaccines during an epidemic of foot-and-mouth disease (FMD) has interested veterinary administrators for many decades. This review assesses the historical uses, successes and failures of vaccinal control, and addresses the questions of where, how, and when to use vaccination against FMD. Approaching the problem in this manner can aid in identifying which tools are likely to be most effective during an epidemic, and how successful a given contingency plan might be. The infection status (endemic, semi-endemic, disease-free) of a region has historically mapped where global vaccination has been implemented according to the generality: endemic>semi-endemic>disease-free. More specifically, biomodels and cost-benefit analyses can indicate when vaccination should be implemented for optimal disease control. Finally, numerous local epidemiological factors will provide useful insights into how vaccinal controls can be used effectively.