Genome Changes in Foot-and-Mouth Disease Virus
The Genomic Changes Associated with the Attenuation in Farm Livestock of Foot-and-Mouth Disease Virus
Tech Area / Field
- AGR-VTH/Vaccines and Theraupetics/Agriculture
3 Approved without Funding
Kyrgyz Agrarian University / Department of Veterinary Sciences, Kyrgyzstan, Bishkek
- The Republican Government Enterprise on the basic of economic control rights “Research Institute for Biological Safety Problems” , Kazakstan, Gvardeiski\nJSC Altyn Tamyr, Kyrgyzstan, Bishkek
Project summaryFoot-and-Mouth Disease (FMD) is a highly contagious viral disease of cattle, sheep, goats and pigs and species of wild ungulates. It is an OIE List A, and is the single most important constraint to international trade in live animals and animal products. All countries that are free of FMD maintain strict import controls, and many of those that have FMD have erradication programmes in place, in order to achieve freedom, and gain access to the lucrative markets of North America, Japan and Europe for their animal exports.
Vaccines against FMD provide, at best, only temporary protection. Because there are seven antigenically distinct serotypes, and within each serotype a spectrum of antigenically variable strains, it is essential to match outbreak strains with vaccine strains. This inevitably delays the implementation of vaccination and frequently requires the development of new vaccine strains. FMD vaccine is produced by growing large quantities of live virulent field virus, followed by concentration, purification and inactivation of the antigen. The antigen is then mixed with adjuvant, and must be stored between 4 and 10oC for its relatively short shelf life. The antigen is prone to disintegration which makes it no longer effective as a vaccine.
There is a requirement for an improved FMD vaccine, with a broad antigenic spectrum, that can be safely produced with minimum disease security. Live attenuated FMD vaccines have been produced in the past, but because they have a history of reverting to virulence, their use was discontinued in most areas of the world. However, with the availability of new molecular techniques, it is possible to investigate the genomic changes associated with the change of FMD virus from virulence to attenuation. If these changes can be fixed, for instnace by incorporating deletions into the genome, it may be possible to develop an attenuated FMD vaccine, which will have all the advantage of a safe, replicating antigen, without the associated danger of reversion to virulence.