title: Evaluation of the efficacy of a new modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (Fostera PRRS) against heterologous PRRSV challenge.
abstract: The objective of this study was to evaluate a new modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (Fostera PRRS, Zoetis, Florham, NJ, USA) that was based on a virulent US PRRSV isolate (P129) attenuated using CD163-expressing cell lines. Sixty-four PRRSV-seronegative 3-week-old pigs were randomly divided into the following four groups: vaccinated challenged (group 1), vaccinated unchallenged (group 2), unvaccinated challenged (group 3), and unvaccinated unchallenged (group 4). The pigs in groups 1 and 2 were immunized with a 2.0 mL dose of modified live PRRSV vaccine at 21 days of age, according to the manufacturer's recommendations. At 56 days of age (0 days post-challenge), the pigs in groups 1 and 3 were inoculated intranasally with 3 mL of tissue culture fluid containing 10(5) 50% tissue culture infective dose (TCID50)/mL of PRRSV (SNUVR090851 strain, fourth passage in MARC-145 cells). Vaccinated challenged pigs exhibited significantly lower (P<0.05) respiratory scores, viremia, macroscopic and microscopic lung lesion scores, and PRRSV-antigen with interstitial pneumonia than unvaccinated challenged pigs. The induction of PRRSV-specific IFN-γ-SCs by the new modified live PRRSV vaccine produced a protective immune response, leading to the reduction of PRRSV viremia. Although the new modified live PRRSV vaccine is not effective against heterologous PRRSV challenge, the new modified live PRRSV vaccine was able to reduce the levels of viremia and nasal shedding, and severity of PRRSV-induced lesions after challenging virus under experimental conditions.
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: votongnum@naver.com.
authors: Changhoon
authors: C
authors: Park
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: kukjinbread@snu.ac.kr.
authors: Hwi Won
authors: HW
authors: Seo
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: redyine@snu.ac.kr.
authors: Kiwon
authors: K
authors: Han
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: kij6988@hanmail.net.
authors: Ikjae
authors: I
authors: Kang
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: swine@snu.ac.kr.
authors: Chanhee
authors: C
authors: Chae
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D019318:Porcine Reproductive and Respiratory Syndrome / Q000097:blood / Q000517:prevention & control* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000472:pathogenicity*; D013552:Swine; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology; D014766:Viremia / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines
keywords: Modified live PRRSV vaccine; Porcine reproductive and respiratory syndrome virus; Respiratory disease; Vaccine efficacy