Inactivated and attenuated vaccines against FCV are available, and most of them use a widely reactive FCV strain denominated F9 that originated from a virus isolated in 1970 [36,37].
FCV is a nonenveloped virus with a positive-sense RNA genome classied in the genus Vesivirus, family Caliciviridae [36,37], which consists of ve related viral genera (Lagovirus, Nebovirus, Norovirus, Sapovirus, and Vesivirus). The term calicivirus is derived from the Greek word calyx (meaning cup or goblet), reecting the fact that many calicivirus strains show visible cup-shaped depressions under electron microscopy. In turn, the genus Vesivirus comprises two recognized species, FCV, and vesicular exanthema of swine virus (VESV, the prototype species of the genus), in addition to the unclassied Vesivirus. Interestingly, VESV (see Chapter 16) causes a vesicular disease in pigs that is clinically indistinguishable from foot-and-mouth disease and swine vesicular disease (see Chapters 8 and 11).