Studies on cellular immunity effection of porcine reproductive and respiratory syndrome vaccine

In order to investigate the protective effect of porcine reproductive and respiratory syndrome virus (PRRSV) CH-1R strain vaccine against the PRRS classic strain JXA1, 14-day old PRRSV-negative piglets were immunized with CH-1R strain vaccine, and challenged with JXA1 virulent strain on 7 days post vaccination. Blood samples were collected for detecting antibodies and lymphocyte factors of CD3+, CD4+, CD8+ on 12, 21, 35, 49, 63 days old piglets. Results showed that on 7 days post vaccination, the ratio of CD4+/lym increased, the ratio of CD8+/lym decreased, the ratio of CD4+/CD8+ increased; two weeks post-infection, the ratio of CD4+/lym and CD8+/lym in the peripheral blood of the piglets of CH-1R strain vaccine immunization group increased, while the ratio of CD4+/CD8+ also increased, which showed that there might have a protective effect of CH-1R strain vaccine against JXA1 strain.