The long-term goal of the PRRS CAP is to develop the tools and deliverable knowledge through integrated strategies for producers that will reduce animal suffering, decrease economic losses to producers, and support stakeholder efforts to control and eliminate PRRSV.
As a result of the complexities and challenges offered by PRRS, the PRRS CAP has taken a global view in developing a strategy to integrate community resources to lessen the impact of PRRS and its eventual elimination. Activities performed by the CAP were identified and prioritized in response to extensive stakeholder input, including meetings with scientists, producers, companies and veterinarians. As a result, activities are divided into three primary research objectives:
Objective 1 (vaccines/immunity)
Objective 2 (epidemiology/ecology)
Objective 3 (host genetics)
It is important to note that there is no objective specifically devoted to diagnostics; however, improved diagnostics, identified by stakeholders as important, is an outcome embedded within all research and extension objectives. CAP research funding is directed at supporting a small number of large multi-year, multi-institutional projects. This is the same funding approach recently adopted by NIFA.
Objective 4 is devoted to extension and includes projects that focus on the control and elimination of PRRSV, including regional elimination projects, standardization of elimination protocols, and novel virus elimination approaches.
Objective 5 is focused on education and outreach, including training fellowships for students from under-represented groups, veterinarians and producers.
Dissemination of CAP activities and successes are by way of scientific publications, review publications, stakeholder meetings and workshops, presentations, and the PRRS CAP website (www.PRRS.org). All PRRS CAP activities are performed in cooperation with the National Pork Board (NPB), which represents 20,000 producers in the U.S.
What is PRRSV?
Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is a stealthy agent that can efficiently enter a swine unit at any stage of production. PRRSV possesses a complex pattern of transmission, including efficient horizontal and vertical transmission.
The virus is transmitted by intranasal, intramuscular, oral, or vaginal routes of exposure. Infected animals shed virus in all bodily secretions. Subclinical, persistent infection in immune competent pigs (carriers) results in the perpetual circulation of virus within herds.
Herd immunity, conferred by vaccination or recovery following infection with field virus, is tenuous because continuous mutation, viral recombination, and evolution of several viral genes may allow the virus to persist in a population. These challenges make traditional approaches to disease control and virus elimination less effective. Modified live virus (MLV) vaccines have not fully met expectations and several deficiencies have been noted, including vaccine virus shedding, persistent infection, incomplete protection, inability to distinguish infected from vaccinated pigs, and potential reversion to virulence.