Project Number: 5430-32000-001-07
Project Type: Specific Cooperative Agreement

Start Date: Aug 01, 2009
End Date: Sep 23, 2012

Objective:
To develop a challenge model for young vaccine age animal and evaluate North American vaccine candidates for the ability to block transmission to mosquitoes following challenge.

Approach:
ARS and CFIA have been working together to develop modern diagnostic tests for detecting RVFV, viral antigen, nucleic acids, and antibodies. During this development, very young sheep and cattle were experimentally infected with RVFV to generate positive diagnostic material. This new study will expand the research to develop a vaccine age challenge model for sheep. The ability of known competent mosquito species to feed on challenge animal to become infected and transmit the virus to susceptible hamsters will be demonstrated. Once this model is confirmed, young sheep will be vaccinated with RVFV MP-12 strain vaccine candidate, held for 28 days then challenged with a virulent strain of RVFV. The ability of the vaccine induced immune response to block the same competent mosquito species fed on challenged animals to become infected and transmit the virus to susceptible hamsters will be evaluated.