The Swine Health Information Center and the Foundation for Food & Agriculture Research have recently funded six new projects to enhance US prevention, preparedness, mitigation and response capabilities for Japanese encephalitis virus (JEV). As a transboundary disease risk for US introduction, JEV is transmitted through the bite of infected mosquitos and can cause reproductive failure, abortions, and stillbirths or weak piglets in swine breeding herds. Recent expansion of JEV into new geographic regions of Australia warrants close investigation to prevent a potential JEV incursion into the US. In the fall of 2024, a total of $1.3M was awarded through the SHIC/FFAR JEV Research Program across six projects now underway.
Announced in February 2024, the SHIC/FFAR JEV Research Program sought to invest in critical research to prevent JEV incursion, ensure rapid detection of JEV if introduced, inform stakeholder response, mitigate production losses on sow farms, identify effective control measures, and develop clear messaging to consumers on the safety of pork. With a goal to address the emerging threat that JEV poses to US swine health, SHIC and FFAR invited proposal submissions from qualified researchers for funding consideration based on value to US pork producers.
A total of 26 proposals from 23 different institutions were received by the submission deadline in April 2024. Six proposals were selected for funding after a highly competitive review process conducted by swine industry stakeholders and subject matter experts. Newly funded projects address the SHIC/FFAR JEV Research Program priorities, including transmission and epidemiology, competent vectors, the role of wildlife, diagnostics, challenge models, and vaccine development.
SHIC/FFAR JEV Research Program projects funded and initiated in response to the RFP include:
Transmission and epidemiology
- Epidemiology of JEV in Australian intensive piggeries
- PI: Brendan Cowled, Ausvet Pty Ltd
- Objectives: 1) Understand the transmission and epidemiology of JEV within farms through a literature review and data analysis of affected farm parameters for model development; 2) Understand and validate the farm-level risk factors for JEV in the Australian outbreak through a qualitative study of expert veterinarians.
Competent vectors
- Vector competence and JEV pathogenesis and immunity in domestic pigs
- PI: Angela Bosco-Lauth, Colorado State University
- Objectives: 1) Evaluate vector competence of JEV in the primary West Nile virus mosquito vectors in the US; 2) Determine susceptibility and pathogenesis of JEV in domestic swine; 3) Assess protective efficacy of WNV vaccination and JEV vaccination against JEV infection in domestic swine; 4) Evaluate cross-neutralization of porcine antibodies against JEV, WNV, and St. Louis encephalitis virus.
Role of wildlife
- Understanding the threat of wild pigs and mosquitoes for JEV transmission to domestic swine farms
- PI: Daniel Peach, University of Georgia
- Objectives: 1) Establish whether wild pigs increase the habitat available to JEV vectors by identifying the mosquito species that breed in wild pig wallows; 2) Determine the extent of access and which mosquito species commonly try to enter sow and wean-to-finish farms; 3) Assess exposure of domestic swine herds to mosquito-borne pathogens associated with wild pigs.
Diagnostics
- Building diagnostic capability for Japanese encephalitis virus in the United States
- PI: Katharine Bossart, Integrated Research Associates, LLC
- Objectives: 1) Assess assay performance using recombinant and inactivated viral antigens from multiple JEV genotypes to build serologic diagnostic capabilities; 2) Create a prototype JEV IgM ELISA kit with all reagents and instructions and create a prototype JEV IgM dot enzyme immunoassay; 3) Develop secondary JEV IgM ELISAs and dot enzyme immunoassays using JEV nonstructural proteins.
Challenge models
- Development of a pregnant sow model to study the pathogenesis of the emergent Japanese encephalitis virus genotype IV
- PI: Juergen Richt, Kansas State University
- Objectives: 1) Develop robust and harmonized in vivo and in vitro methods for comparative analysis of infected pregnant sows across two study centers; 2) Conduct JEV infection trials at three gestational timepoints at each site; 3) Determine the pathobiological features of in utero infection and compare across the two study centers.
Vaccine development
- Translation of the highly safe, pure and potent IMOJEV® live, attenuated chimeric vaccine against JE in humans for prevention of JEV infection and disease in swine
- PI: Thomas Monath; Substipharm Biologics SA
- Objectives: 1) Demonstrate safety and immunogenicity of IMOJEV in swine; 2) Demonstrate efficacy of IMOJEV in protecting pigs from challenge with JEV; 3) Determine minimum effective dose for immunization with IMOJEV; 4) Provide quality assurance and quality control; 5) Develop a product development plan to meet product licensing requirements.
Awarded projects are nine to 24 months in duration; research results will be shared as soon as they become available. In partnership with FFAR, this effort helps SHIC fulfill its mission to generate new intelligence for preventing, preparing for, and responding to emerging swine disease threats. Understanding the potential impacts of JEV on pork production is critical to protecting the health of the US swine herd as well as mitigating the risk of this emerging disease.
Foundation for Food & Agriculture Research
The Foundation for Food & Agriculture Research (FFAR) builds public-private partnerships to fund bold research addressing big food and agriculture challenges. FFAR was established in the 2014 Farm Bill to increase public agriculture research investments, fill knowledge gaps and complement the U.S. Department Agriculture’s research agenda. FFAR’s model matches federal funding from Congress with private funding, delivering a powerful return on taxpayer investment. Through collaboration and partnerships, FFAR advances actionable science benefiting farmers, consumers and the environment.
Swine Health Information Center
The Swine Health Information Center, launched in 2015 with Pork Checkoff funding, protects and enhances the health of the US swine herd by minimizing the impact of emerging disease threats through preparedness, coordinated communications, global disease monitoring, analysis of swine health data, and targeted research investments. As a conduit of information and research, SHIC encourages sharing of its publications and research. Forward, reprint, and quote SHIC material freely. For more information, visit http://www.swinehealth.org or contact Dr. Megan Niederwerder at mniederwerder@swinehealth.org or Dr. Lisa Becton at lbecton@swinehealth.org.