title: Efficacy of Fostera PRRS modified live virus vaccine against a Canadian heterologous virulent field strain of porcine reproductive and respiratory syndrome virus.
abstract: Vaccination is a useful option to control infection with porcine reproductive and respiratory syndrome virus (PRRSV), and several modified live-PRRSV vaccines have been developed. These vaccines have shown some efficacy in reducing the incidence and severity of clinical disease as well as the duration of viremia and virus shedding but have failed to provide sterilizing immunity. The efficacy of modified live-virus (MLV) vaccines is greater against a homologous strain compared with heterologous PRRSV strains. The objective of this study was to evaluate the efficacy of Fostera PRRS MLV vaccine in protecting against challenge with a heterologous field strain widely circulating in the swine herds of eastern Canada. Forty-six piglets were divided into 4 groups: nonvaccinated-nonchallenged; nonvaccinated-challenged; vaccinated-challenged; and vaccinated-nonchallenged. The animals were vaccinated at 23 d of age with Fostera PRRS and challenged 23 d later with a heterologous field strain of PRRSV (FMV12-1425619). Overall, the vaccine showed some beneficial effects in the challenged animals by reducing the severity of clinical signs and the viral load. A significant difference between nonvaccinated and vaccinated animals was detected for some parameters starting 11 to 13 d after challenge, which suggested that the cell-mediated immune response or other delayed responses could be more important than pre-existing PRRSV antibodies in vaccinated animals within the context of protection against heterologous strains.
authors.affiliation: Swine and Poultry Infectious Diseases Research Center and The Research Group on Infectious Diseases of Swine, Faculté de médecine vétérinaire, Université de Montréal, 3200, rue Sicotte, Saint-Hyacinthe, Quebec J2S 7C6.
authors.forename: Christian
authors.initials: C
authors.lastname: Savard
authors.affiliation: Swine and Poultry Infectious Diseases Research Center and The Research Group on Infectious Diseases of Swine, Faculté de médecine vétérinaire, Université de Montréal, 3200, rue Sicotte, Saint-Hyacinthe, Quebec J2S 7C6.
authors.forename: Fernando
authors.initials: F
authors.lastname: Alvarez
authors.affiliation: Swine and Poultry Infectious Diseases Research Center and The Research Group on Infectious Diseases of Swine, Faculté de médecine vétérinaire, Université de Montréal, 3200, rue Sicotte, Saint-Hyacinthe, Quebec J2S 7C6.
authors.forename: Chantale
authors.initials: C
authors.lastname: Provost
authors.affiliation: Swine and Poultry Infectious Diseases Research Center and The Research Group on Infectious Diseases of Swine, Faculté de médecine vétérinaire, Université de Montréal, 3200, rue Sicotte, Saint-Hyacinthe, Quebec J2S 7C6.
authors.forename: Younes
authors.initials: Y
authors.lastname: Chorfi
authors.affiliation: Swine and Poultry Infectious Diseases Research Center and The Research Group on Infectious Diseases of Swine, Faculté de médecine vétérinaire, Université de Montréal, 3200, rue Sicotte, Saint-Hyacinthe, Quebec J2S 7C6.
authors.forename: Sylvie
authors.initials: S
authors.lastname: D'Allaire
authors.affiliation: Swine and Poultry Infectious Diseases Research Center and The Research Group on Infectious Diseases of Swine, Faculté de médecine vétérinaire, Université de Montréal, 3200, rue Sicotte, Saint-Hyacinthe, Quebec J2S 7C6.
authors.forename: Marie-Odile
authors.initials: MO
authors.lastname: Benoit-Biancamano
authors.affiliation: Swine and Poultry Infectious Diseases Research Center and The Research Group on Infectious Diseases of Swine, Faculté de médecine vétérinaire, Université de Montréal, 3200, rue Sicotte, Saint-Hyacinthe, Quebec J2S 7C6.
authors.forename: Carl A
authors.initials: CA
authors.lastname: Gagnon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000918:Antibody Specificity; D002170:Canada / Q000453:epidemiology; D015967:Gene Expression Regulation, Viral; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D019318:Porcine Reproductive and Respiratory Syndrome / Q000453:epidemiology / Q000517:prevention & control* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000472:pathogenicity*; D013552:Swine; D014765:Viral Vaccines / Q000276:immunology*; D014774:Virulence
chemical_list: D000914:Antibodies, Viral; D014765:Viral Vaccines