Vaccination against foot-and-mouth disease virus: strategies and effectiveness.

Although present conventional foot-and-mouth disease (FMD) vaccines can prevent clinical disease, protection is short lived ( approximately 6 months), often requiring frequent revaccination for prophylactic control, and vaccination does not induce rapid protection against challenge or prevent the development of the carrier state. Furthermore, it is clear that the clinical protection depends upon the length of immunization and the duration of exposure/challenge methods. This review summarizes the present and future strategies for FMD control in endemic and FMD-free countries, the effectiveness of FMD vaccines in cattle, sheep and pigs, new methods for selecting vaccine strains, suggestions for alternative methods of vaccine testing, suggestions for the development of new-generation efficacious vaccines and their companion tests to differentiate infection in vaccinated animals.