The exact frequency of booster vaccinations depends on the state of the epidemic and the exposure of animals to live virus which is expected. After vaccination, animals are unlikely to develop foot and mouth disease unless already infected at the time of vaccination. Vaccine does not work if it is administered after an animal has caught the disease, though it may mask the clinical signs of infection. There is always a risk that this will happen, as there is an incubation period of about a week between catching the disease and showing the signs. An animal vaccinated during this period will still have foot and mouth disease and be capable of passing it on to others.
Females pass on immunity to their offspring through their milk.
If young animals are vaccinated while they have maternal antibodies in their bloodstream, the vaccine immunity has to break through the maternal immunity, so protection is not certain. There is a period while the maternal antibodies are wearing off when vaccine may still not work, but the young animal is vulnerable to the disease, if exposed to infection. Impact on Different Species 9. Across the world, many farmers use vaccination to protect their stock, particularly in areas where foot and mouth disease is endemic in the wildlife or among domesticated animals. It is most commonly used on cattle, because they are more valuable than sheep.