Translations:Adventist Youth Honors Answer Book/Outdoor Industries/Dairying/41/en
From Pathfinder Wiki
One of the difficulties in vaccinating against FMD is the huge variation between viral strains. There is no cross-protection between strains (meaning that a vaccine for one strain won't protect against any others) and in addition, two strains within a given strain may have nucleotide sequences that differ by as much as 30% for a given gene. This means that FMD vaccines must be highly specific to the strain involved. Vaccination only provides temporary immunity that lasts from months to years.
