Project Number: 5430-32000-005-00
Project Type: Appropriated

Start Date: Feb 01, 2012
End Date: Jan 31, 2017

Objective:
1. Identify epidemiological factors affecting disease outbreak and inter-epizootic maintenance of RVFV. Sub-objective 1A: Create a network based stochastic model that accounts for mosquitoes, cattle and humans to determine the best mitigation strategies in the event of an outbreak. Sub-objective 1B: Develop tools for rapid detection and characterization of emergent viruses. 2. Identify factors associated with RVFV infection, pathogenesis and maintenance. Sub-objective 2A: Develop RVFV “vector-transmitted” infectious models in target ruminant species to facilitate studies of disease pathogenesis, disease transmission and vaccine efficacy. Sub-objective 2B: Identify mammalian host innate and adaptive responses to insect transmitted RVFV. 3. Develop and validate vaccine strategies for preventing RVFV epizootics. Sub-Objective 3.A. Develop needle-free vaccine platforms that reduce the time to effective onset of immunity. Sub-Objective 3.B. Develop vaccine platforms that do not require refrigeration for extended periods of time.

Approach:
The potential introduction of Rift Valley fever (RVF) virus (RVFV) is the most significant arthropod-borne animal disease threat to U.S. livestock according to the USDA-APHIS National Veterinary Stockpile (NVS) Steering Committee. A number of challenges exist for the control and prevention of RVF in the areas of disease surveillance, diagnostics, vaccines and vector control. RVFV is the third biological threat agent on the NVS Steering Committee’s priority list for generation and stockpiling of countermeasures for diagnosis, vaccination, and insect control. Understanding the epidemiological factors affecting disease outbreak and the inter-epizootic maintenance of RVFV is necessary for the development of appropriate countermeasures strategies. This includes the ability to detect and characterize emergent viruses since RVFV is an RNA virus and could evolve to adapt to a new environment. Also, the proposed research will identify determinants of RVFV infection, pathogenesis and maintenance in mammalian and insect vector hosts. Information derived from these studies will also provide a better vaccine evaluation challenge model. Vaccine formulations will be developed to improve immunogenicity, onset of immunity and stability to provide better response to outbreaks and prevent RVFV epizootics. The overall goals of this project are to utilize the unit’s unique multidisciplinary expertise to fill knowledge gaps about the interepidemic cycle of RVFV and provide the tools necessary for detecting, controlling and eradicating RVFV should it be introduced into the U.S.