About the project


The U.S. Defense Advanced Research Projects Agency (DARPA) funds the PREEMPT program, a 3.5 year initiative that seeks to preserve the health of U.S. troops and communities around the world by containing emerging infectious diseases in animal populations before they can threaten humans.

A researcher in full protection gear holds a rat in a sample bag.
Field teams in Sierra Leone will begin collecting and testing samples from Mastomys rats, a widespread local rodent and known reservoir for Lassa virus. (Courtesy PREDICT)

As one of only five teams selected to participate in PREEMPT, UC Davis and its project partners will contribute research concentrating on Lassa virus and Ebola virus. The research team aims to predict spillover potential and design a novel animal vaccination that will prevent emerging pathogenic threats in high-risk infectious disease areas such as Sierra Leone and more broadly throughout Africa.

Currently, emerging viral pathogens are managed reactively, relying on active surveillance and post-emergence response. Because human vaccinations are most effective before the start of an epidemic, the capability to preemptively lower outbreak potential through animal reservoir vaccination could significantly reduce illnesses among local communities. At the same time, proactive interventions enhance international peacekeeper capabilities to manage security threats by eliminating infectious disease threats from the local environment.

Our project proposes to strike at viral pathogens like Lassa fever virus and Ebola virus before they emerge by eliminating them from their animal reservoirs and hosts from which they frequently spillover into human populations. To do this, the team will develop computer models that predict the locations and conditions that promote virus emergence and then identify key opportunities for preemptive pathogen elimination using animal vaccines. To accomplish these goals, extensive field-work in Sierra Leone will be coupled with laboratory-based studies in the United States, Europe and Australia to develop targeted vaccine countermeasures to these significant human health threats.

Concept and Approach

  • Design predictive models to determine risk of Lassa fever and Ebola exposure risk for local communities and security forces in Sierra Leone
  • Predict virus emergence and potential vaccination delivery bottlenecks using field studies of Lassa virus in Sierra Leone and advanced mathematical and computational modeling
  • Develop and validate prototype animal vaccine candidates in contained, biosecure laboratory facilities
  • Develop the first vaccines targeting the animal reservoirs and hosts of Lassa and Ebola viruses using a Cytomegalovirus (CMV) vaccine platform
  • Pioneer self-limiting vaccine concepts using flanking repeats within the CMV vaccine platform
  • Determine the potential for virus risk elimination using these vaccines
  • Develop forecasting tools for proactive interventions relying on animal reservoir vaccines