Highly contagious foot-and-mouth disease virus (FMDV) is responsible for devastating outbreaks of the disease among cloven-hoofed animals. Foot-and-mouth disease (FMD) can be controlled by slaughter of infected and exposed herds, or by vaccination. Slaughter has been the preferred action in countries that are normally free of the disease because under the current regulations of the Office International des Epizooties (OIE) the presence of vaccinated animals leads to loss of FMD-free status and access to export markets [1]. The current vaccines consist of partly purified inactivated virus preparations. These vaccines are successful in prevent- ing the disease, but present the risks of virus escape from production plants [2]. Moreover, vaccination compromises the ability to detect infection by the internationally accepted