All current commercial PRRS vaccines are formulated using natural PRRSV strains and are not adequately effective for PRRS control and eradication. This project proposed to develop a PRRSV vaccine strain that could offer broader cross-protection. The study applied an algorithm to design an artificial PRRSV genome based on virus isolates to represent the widest genetic diversity of strains circulating in U.S. swine herds. We chemically synthesized this computer-designed PRRSV genome and applied genetics techniques to generate a viable PRRSV-CON virus. Data showed that PRRSV-CON replicates as efficiently in cell culture and pigs as PRRSV-FL12. Two experiments, each involving three groups of weaned pigs, evaluated the cross-protective capacity of PRRSV-CON. Group 1 served as non-immunized control, groups 2 and 3 were infected with PRRSV-CON or the PRRSV-FL12. At 52 days post-infection, all pigs were challenged with a heterologous PRRSV isolate. [Source: Pork Checkoff Research Review]
Points:
- Genetic variation among porcine reproductive and respiratory syndrome virus (PRRSV) strains is an obstacle in developing a broad-protection vaccine.
- Results showed that PRRSV-CON offers broader coverage than prototype PRRSV-FL12.
- PRRSV-CON could serve as a candidate to develop a vaccine with broader cross-protection.
Source: AASV