|NIEDERWERDER, MEGAN - Kansas State University|
|BHUPINDER, BAWA - Kansas State University|
|SERAO, NVL - Iowa State University|
|TRIBLE, B - Kansas State University|
|KERRIGAN, M - Kansas State University|
|DEKKERS, JCM - Iowa State University|
|ROWLAND, RRR - Kansas State University|
Submitted to: Clinical and Vaccine Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2015
Publication Date: 10/7/2015
Publication URL: https://handle.nal.usda.gov/10113/5235114
Citation: Niederwerder, M., Bhupinder, B., Serao, N., Trible, B., Kerrigan, M., Lunney, J.K., Dekkers, J., Rowland, R. 2015. Vaccination with a porcine reproductive and respiratory syndrome modified live virus vaccine followed by challenge with PRRSV and porcine circovirus type 2 protects against PRRS but enhances PCV2 replication and parthogenesis. Clinical and Vaccine Immunology. 22(12):1244-54.
Interpretive Summary: Young pigs get respiratory infections due frequently to infections involving porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2). Vaccination for PRRS decreases pathology for that infection; however, our new studies show that if there's a co-infection of PRRSV and PCV2 pigs suffer. Vaccinated pigs are protected from PRRS but they exhibit increased clinical pathology including signs of porcine circovirus-associated disease (PCVAD), decreased weight gain, and increased mortality. This data shows that the early benefits of PRRSV vaccination were outweighed by the later amplification of PCVAD.
Technical Abstract: Co-infections involving porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) contribute to a group of disease syndromes known as porcine circovirus-associated disease (PCVAD). Presumably, PRRSV infection enhances PCV2 replication as a result of modulation of host immunity. The purpose of this study was to evaluate PCV2 replication and pathogenesis in pigs vaccinated with a PRRS modified live virus (MLV) vaccine and subsequently challenged with a combination of PRRSV and PCV2. During the early post-challenge period, PRRSV-associated clinical signs were decreased and average daily gain (ADG) was increased in the vaccinated group, demonstrating the protective effect of PRRS vaccination. However, during the later post-challenge period, the vaccinated group showed greater numbers of pigs with increased PCV2 viremia, decreased ADG, increased PCVAD clinical signs, and increased mortality. In this disease model, the early benefits of PRRSV vaccination were outweighed by the later amplification of PCVAD.