Effect of 4 commercial PRRS vaccine on the CSFV vaccine antibody response

PRRS and CSFV vaccine are both widely used in China. Most of time they will be vaccinated on piglets apart 2 weeks. Studies have shown that vaccinating CSFV vaccine 2 days after PRRS vaccination will reduce CSFV immunity response.From our farm routine antibody monitor program, we found CSFV antibody positive rate always low(< 30%), so we designed to investigate if vaccinated piglets CSFV vaccine 2 weeks after PRRS vaccination still influence CSFV antibody response.

164 piglets from 15 littles were randomly separated into 5 groups. Group A (n=32) vaccinated local "classic strain" PRRS vaccine, Group B (n=30) vaccinated another local "classic strain" PRRS vaccine, Group C(n=33) vaccinated highly pathogenic strain PRRS vaccine, Group D(n=35) vaccinated Ingelvac PRRS MLV, Group E (n=34) were control. Group A, B, C, D vaccinated PRRS vaccine at 15 days, and C-strain CSFV vaccinate at 30 days; control group just vaccinated CSFV vaccine at 30 days. After wean, every group were separated into different pens and not mixed. All the management and other vaccination program for these 5 groups are all the same. serum samples were collected from all piglets 35 days after CSFV vaccinattion. Serum concentration of CSFV antibody was determined by IDEXX ELISA kit (IDEXX CSF Sero). The cut off value of the CSF ELISA is 0.4 in blocking rate.

CSFV antibody positive rate of group A is 25%, group B is 20%, group C is 21.1%, Group D is 82.9%, control group is 85.3%. P value between Group D and Group A is < 0.0001, Group D and Group B is < 0.0001, Group D and Group C is < 0.0001, Group D and control is 0.8264. 3. From this study, we found local commercial PRRS vaccine will significant reduce CSF vaccine antibody response even 2 weeks apart vaccination, meanwhile, Ingelvac PRRS MLV is safe to use and not influencing the CSF antibody response apart 2 weeks vaccination.

Some farms get confused to low CSFV antibody positive rate after vaccination even choose high quality commercial CSFV vaccine. From this study we found some PRRS vaccine will reduce CSFV vaccine antibody response, farmers should also pay attention to PRRS vaccine’s role on CSFV antibody response.

Disclosure of Interest: None Declared.