#08-146

Complete

Date Full Report Received

10/01/2010

Date Abstract Report Received

10/01/2010

Investigation

Institution:
Primary Investigator:
Several porcine circovirus type 2 (PCV2) vaccines are now commercially available and have been shown to be effective at decreasing the occurrence of porcine circovirus associated disease (PCVAD). Many herds are coinfected with PCV2 and porcine reproductive and respiratory syndrome virus (PRRSV). Some producers and veterinarians are concerned that if pigs are vaccinated for PCV2 at or near the time they typically are infected with PRRSV, the efficacy of the PCV2 vaccine will be compromised. The impact of PRRSV on PCV2 vaccination is unclear and has not been investigated under controlled conditions. The objective of the present study was to determine whether the presence of PRRSV viremia has an effect on the efficacy of commercial PCV2 vaccinations. Three-week-old PCV2-negative conventional pigs with passively-derived anti-PCV2-antibodies were either vaccinated with one of three commercial PCV2 vaccines or left non-vaccinated. A portion of the pigs were infected with PRRSV one week prior to PCV2 vaccination. To determine vaccine efficacy, a PCV2 challenge was conducted at 8 weeks of age. PCV2 vaccination regardless of PRRSV infection status at the time of vaccination was similarly effective in inducing an anti-PCV2-IgG response in the presence of maternally-derived immunity and in protecting the pigs from PCV2 challenge as determined by reduction in PCV2 viremia and reduction of prevalence and amount of PCV2 antigen in lymphoid tissues compared to non-vaccinated pigs. The results indicate that acute PRRSV infection at the time of PCV2 vaccination has no adverse effect on PCV2 vaccine efficacy.