Abstract Foot-and-mouth disease(FMD) emergency vaccines was a high potency vaccine (usually ≥6 protective dose 50 (PD50)) ,which had wide cross-immunity within FMD serotypes, and could induce rapid protective immunity after animals were inoculated 3～4 days, moreover, used emergency vaccine could prevent or decrease local virus replicating in throat and other sites, where is adapt to FMDV existing, so dramatically reduced the amount of virus released into environment and occurrenced of persistently infected "carrier" animals following vaccination, furthermore, the antibody induced by emergency vaccines maintaining longer than traditional inactived vaccines. The succeed using of emergency vaccines by Netherlands and Greece in 2001 and 90 times, respectively, indicated that emergency vaccines was advantage of defending emergency conditions. Lately, several studies carried out by world foot-and-mouth disease referenced laboratory and other countries approving that emergency vaccines had unexampled preponderance whether in preventing direct infection or indirect infection .At present, emergency vaccines were considered by UK and other free Foot-and-mouth disease countries as an additional means for control. This article described emergency vaccines from its antigenic coverage、immunity potency and rapid immunity mechanism.
|
