A new class of porcine reproductive and respiratory syndrome (PRRS) autogenous vaccine produced in a novel porcine macrophage cell line

Swine morbidity and mortality caused by porcine reproductive and respiratory syndrome (PRRS) virus is a threat to the U.S. pork industry causing losses of $664 million last year that may exceed $700 million in 2014. Vaccines against PRRS virus have failed to stem the occurrence of PRRS in U.S. herds. Here we propose to ascertain the technical feasibility of developing an effective autogenous (killed virus) vaccine. Aptimmune's approach to prepare an atuogenous PRRS virus vaccine consists of using the proprietary porcine alveolar macrophage cell line, named ZMAC, as the cell substrate for both the isolation of field PRRS virus from a clinical sample and the production of the PRRS virus stocks to produce the viral antigen for the vaccine. Since the ZMAC cell line can be used to reliably and swiftly produce autogenous PRRS vaccines from wild-type (field) PRRS virus, it provides to Aptimmune a major competitive advantage. Since the ZMAC cell line is of the same species as the animal in which the vaccine will be used we have termed this new class of PRRS autogenous vaccine as Homologous Cell Autogenous Vaccine (HCAV).We have selected several commercially available adjuvants to formulate our HCAV. We will test these alternative vaccine formulations for their ability to stimulate virus-inhibitory immunity. We expect that our strategy to explore several alternative formulations of a PRRS HCAV will lead to the identification of an effective autogenous vaccine capable of eliciting strong levels of protective immunity against PRRS virus. The expected results of Phase I include: 1) a process for production of an autogenous virus vaccine starting from a clinical sample in 5 weeks or less; 2) identify an optimal formulation for a PRRS HCAV that elicits strong virus inhibitory immunity.The expected outcome is the development of a production process to manufacture in a timely manner an effective autogenous vaccine against PRRS virus. Ultimately, the commercial availability of an effective autogenous PRRS vaccine should result in application of effective management strategies that successfully control the spread of PRRS virus and incidence of PRRS outbreaks. The availability of an effective vaccine against PRRS will mitigate the significant economic impact that this disease has to the American pork industry and thus increase its profitability.