Location: Foreign Animal Disease Research2013 Annual Report
1a. Objectives (from AD-416):
This collaborative research project seeks to determine whether different routes of application of emergency oil emulsion Foot-and-Mouth Disease (FMD) vaccines lead to varying efficacy in Merino sheep and prevent the establishment of the carrier state. Specific objectives include: 1. Determine the optimal route of inoculation for sheep to induce reproducible clinical disease. 2. Determine the optimal route of vaccine application in sheep using emergency, high potency double oil emulsion serotype O FMD vaccine. 3. Determine the protection afforded by the best route as determined above with heterologous live virus challenge. 4. Determine if vaccination prevents the establishment of a carrier state. 5. Determine what dose of vaccine best prevents the establishment of a carrier state.
1b. Approach (from AD-416):
1. A comparison study of intranasal instillation and aerosol infection using a commercially available aerosol delivery system to determine the most reproducible way of infecting Merino sheep will be conducted. 2. A delivery study utilizing decreasing doses of emergency serotype O vaccine via the intra-muscular and intra-dermal routes will be conducted. The immune responses of each will be studied using in vitro assays. 3. In vivo vaccination studies will be conducted using the best methods determined above and challenge with a heterlogous virus to determine vaccine efficacy. 4. To determine carrier state activity, vaccinated and infected sheep will be studied for at least 35 days post infection. Studies will also include minimal protective dose.
3. Progress Report:
Foot-and-Mouth Disease Virus (FMDV) is a highly contagious disease effecting livestock inclusive of sheep. This collaborative research project seeks to determine the efficacy of commercially available vaccines to protect sheep from clinical disease and long term carrier status associated with infection by globally relevant FMDV strains. Study design was discussed and finalized to include three separate experiments inclusive of; challenge route establishment, vaccination studies to determine the optimal route of vaccination as determined by antibody response and a vaccination study to determine the best route of vaccine application utilizing strains 01 Manisa and O/Korea 2010. To date, the sheep have been procured and acclimated to meet the needs for the three-phase experiment. Clinical data and samples were compiled. Preliminary results indicate the 2010 FMDV serotype O from Korea is highly infectious in sheep via nasopharyngeal, aerosol, and direct coronary band inoculation. During the rest of FY 2013 the optimal route of vaccination studies will be conducted. A post doctoral fellow from CSIRO will be coming to ARS, PIADC in August 2013 to take part in these studies and will remain during the third set of studies set for FY 2014. No technologies were transferred or publications produced in FY 2013 in support of this project.