Porcine reproductive and respiratory syndrome (PRRS) is the most economically significant disease affecting U.S. swine production. PRRS costs the U.S. pork industry $664 million each year in production losses and nearly another $478 million in veterinary, biosecurity and other outbreak related costs. That’s a total of more than $1.14 billion per year, or over $3.1 million per day.
The disease’s economic impact occurs through a significant increase in death loss, a significant decrease in average daily weight gain, and increased use of ineffective medications. Industry cost estimates for the performance loss and medication is $4.32 per pig.
PRRS is a viral disease that causes a decrease in reproductive performance in breeding animals and respiratory disease in pigs of any age. Pregnant sows infected with PRRS can deliver PRRS virus–infected piglets. PRRS can be transmitted from infected piglets or sows to other piglets. The cycle of virus shedding and infection can continue well into the nursery phase in situations in which the sow herd is actively infected. Piglets that are born weak can experience mortalities exceeding 60%, with death usually occurring in the first week of life. 100% mortality should be expected for piglets born prematurely. PRRSV infection in weaned pigs is characterized by fever, pneumonia, lethargy, and failure to thrive.
Current Unmet Medical Need
The virus has posed a recurring challenge for the pork industry with 20 to 40 percent of average breeding herds in the US experiencing outbreaks in a given year.
Current vaccines are ineffective because they:
-Cannot provide sustainable disease control.
-Don’t offer enough protection against the immune evasion of the virus and the antigenic heterogeneity or diversity of field strains. Multiple strains are circulating.
-Afford low efficacy with current live attenuated and inactivated vaccines. The live attenuated vaccines have protective value against PRRS clinical disorders, but cannot prevent the disease or shorten persistent infection in individual pigs, resulting in reversion to full pathogenic virus and long-term circulation within swine herds.
-Require greater antigen dosage.
-Have increased level of safety concerns relative to more modern vaccines, like those at PAH
PAH Medical Solution and Competitive Advantage
IMT504 has the potential to provide a PRRS vaccine that:
-Drives adaptive immune responses with very high antibodies, antibody persistence, and longevity.
-Has broader protection against diverse virus strains.
-Has a VLP/Virosomal construction that is not alive; therefore, there is no risk for reversion to full pathogenic virus within the herd.
-Offers significant antigen sparing. Current vaccines need a much greater amount of each vaccine component.