title: Pigs immunized with Chinese highly pathogenic PRRS virus modified live vaccine are protected from challenge with North American PRRSV strain NADC-20.
abstract: Modified live virus (MLV) vaccines developed to protect against PRRSV circulating in North America (NA) offer limited protection to highly pathogenic (HP) PRRSV strains that are emerging in Asia. MLV vaccines specific to HP-PRRSV strains commercially available in China provide protection to HP-PRRSV; however, the efficacy of these HP-PRRSV vaccines to current circulating NA PRRS viruses has not been reported. The aim of this study is to investigate whether pigs vaccinated with attenuated Chinese HP-PRRSV vaccine (JXA1-R) are protected from infection by NA PRRSV strain NADC-20. We found that pigs vaccinated with JXA1-R were protected from challenges with HV-PRRSV or NADC-20 as shown by fewer days of clinical fever, reduced lung pathology scores, and lower PRRS virus load in the blood. PRRSV-specific antibodies, as measured by IDEXX ELISA, appeared one week after vaccination and virus neutralizing antibodies were detected four weeks post vaccination. Pigs vaccinated with JXA1-R developed broadly neutralizing antibodies with high titers to NADC-20, JXA1-R, and HV-PRRSV. In addition, we also found that IFN-α and IFN-β occurred at higher levels in the lungs of pigs vaccinated with JXA1-R. Taken together, our studies provide the first evidence that JXA1-R can confer protection in pigs against the heterologous NA PRRSV strain NADC-20.
authors.affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Galliher-Beckley
authors.affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA.
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Bates
authors.affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Madera
authors.affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Waters
authors.affiliation: Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA.
authors.forename: Jerome
authors.initials: J
authors.lastname: Nietfeld
authors.affiliation: Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA.
authors.forename: Jamie
authors.initials: J
authors.lastname: Henningson
authors.affiliation: State Key Laboratory of Biotechnology and Bio-products Development for Animal Epidemic Prevention, South China Agricultural University, Guangzhou, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: He
authors.affiliation: State Key Laboratory of Agro-biotechnology, China Agriculture University, Beijing, China.
authors.forename: Wenhai
authors.initials: W
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Biotechnology and Bio-products Development for Animal Epidemic Prevention, South China Agricultural University, Guangzhou, China.
authors.forename: Ruiai
authors.initials: R
authors.lastname: Chen
authors.affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA. Electronic address: jshi@ksu.edu.
authors.forename: Jishu
authors.initials: J
authors.lastname: Shi
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002681:China; D016898:Interferon-alpha / Q000032:analysis; D016899:Interferon-beta / Q000032:analysis; D008168:Lung / Q000473:pathology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D012720:Severity of Illness Index; D013552:Swine; D013997:Time Factors; D016896:Treatment Outcome; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D019562:Viral Load; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014766:Viremia
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D016898:Interferon-alpha; D014613:Vaccines, Attenuated; D014765:Viral Vaccines; D016899:Interferon-beta
keywords: Highly pathogenic PRRS virus; JXA-1; NADC-20; Pig; Vaccine