title: Comparison of two genetically distant type 2 porcine reproductive and respiratory syndrome virus (PRRSV) modified live vaccines against Vietnamese highly pathogenic PRRSV.
abstract: Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) known as pig high fever disease was first reported in China and has spread rapidly in neighboring southeastern Asian countries. The objective of this study was to evaluate the efficacy of a new type 2 PRRSV modified live vaccine (vaccine A) against a challenge with a HP-PRRSV and to compare the efficacy of two genetically distant type 2 PRRSV modified vaccines (vaccine A for lineage 8 and vaccine B for lineage 5) against HP-PRRSV (lineage 8) challenge. Pigs were divided into 4 groups (n=12/group); vaccinated challenged (2 groups), unvaccinated challenged, and unvaccinated unchallenged groups. Regardless of vaccines, vaccinated challenged pigs showed significantly lower (P<0.05) mean rectal temperatures and respiratory scores, levels of HP-PRRSV viremia, and lung lesions and HP-PRRSV antigens within lung lesions compared to unvaccinated challenged pigs. Vaccinated challenged pigs had significantly higher (P<0.05) numbers of interferon-γ secreting cells (IFN-γ-SC) compared to unvaccinated challenged pigs. Significant differences were also found when comparing two type 2 PRRSV vaccines after HP-PRRSV challenge. The use of type 2 PRRSV vaccine A was able to significantly reduce fever when compared to type 2 PRRSV vaccine B in vaccinated challenged pigs. Vaccination of pigs with vaccine A reduced viral loads in their blood and induced higher numbers of HP-PRRSV-specific IFN-γ-SC than vaccination of pigs with vaccine B. This study demonstrates partial protection of two genetically distant type 2 PRRSV vaccines against HP-PRRSV challenge in growing pigs.
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea; Faculty of Animal Husbandry and Veterinary Medicine, Nonglam University, Thu Duc District, Ho Chi Minh City, Vietnam.
authors.forename: Duy Tien
authors.initials: DT
authors.lastname: Do
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Changhoon
authors.initials: C
authors.lastname: Park
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Kyuhyung
authors.initials: K
authors.lastname: Choi
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Jiwoon
authors.initials: J
authors.lastname: Jeong
authors.affiliation: Faculty of Animal Husbandry and Veterinary Medicine, Nonglam University, Thu Duc District, Ho Chi Minh City, Vietnam.
authors.forename: Toan Tat
authors.initials: TT
authors.lastname: Nguyen
authors.affiliation: Faculty of Animal Husbandry and Veterinary Medicine, Nonglam University, Thu Duc District, Ho Chi Minh City, Vietnam.
authors.forename: Khang Duong
authors.initials: KD
authors.lastname: Nguyen
authors.affiliation: Faculty of Animal Husbandry and Veterinary Medicine, Nonglam University, Thu Duc District, Ho Chi Minh City, Vietnam.
authors.forename: Dai Tan
authors.initials: DT
authors.lastname: Vo
authors.affiliation: 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.forename: Chanhee
authors.initials: C
authors.lastname: Chae
mesh_terms: D000818:Animals; D001483:Base Sequence; D016000:Cluster Analysis; D007371:Interferon-gamma / Q000276:immunology; D008969:Molecular Sequence Data; D010802:Phylogeny; D019318:Porcine Reproductive and Respiratory Syndrome / Q000517:prevention & control*; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics* / Q000276:immunology* / Q000472:pathogenicity; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D034421:Sus scrofa / Q000276:immunology*; D013552:Swine; D014611:Vaccination / Q000662:veterinary*; D014613:Vaccines, Attenuated / Q000276:immunology; D014744:Vietnam; D014765:Viral Vaccines / Q000276:immunology*; D014766:Viremia / Q000276:immunology
chemical_list: D014613:Vaccines, Attenuated; D014765:Viral Vaccines; D007371:Interferon-gamma
keywords: Comparison; Highly pathogenic porcine reproductive and respiratory syndrome virus; Protection; Vaccine