title: Vaccination with a genotype 1 modified live vaccine against porcine reproductive and respiratory syndrome virus significantly reduces viremia, viral shedding and transmission of the virus in a quasi-natural experimental model.
abstract: The present study assessed the efficacy of vaccination against genotype 1 porcine reproductive and respiratory syndrome virus (PRRSV) in terms of reduction of the transmission. Ninety-eight 3-week-old piglets were divided in two groups: V (n=40) and NV (n=58) that were housed separately. V animals were vaccinated with a commercial genotype 1 PRRSV vaccine while NV were kept as controls. On day 35 post-vaccination, 14 NV pigs were separated and inoculated intranasally with 2 ml of a heterologous genotype 1 PRRSV isolate ("seeder" pigs, SP). The other V and NV animals were distributed in groups of 5 pigs each. Two days later, one SP was introduced into each pen to expose V and NV to PRRSV. Sentinel pigs were allocated in adjacent pens. Follow-up was of 21 days. All NV (30/30) became viremic after contact with SP while only 53% of V pigs were detected so (21/40, p<0.05). Vaccination shortened viremia (12.2±4 versus 3.7±3.4 days in NV and V pigs, respectively, p<0.01). The 50% survival time for becoming infected (Kaplan-Meier) for V was 21 days (CI95%=14.1-27.9) compared to 7 days (CI95%=5.2-8.7) for NV animals (p<0.01). These differences were reflected in the R value as well: 2.78 (CI95%=2.13-3.43) for NV and 0.53 (CI95%=0.19-0.76) for V pigs (p<0.05). All sentinel pigs (10/10) in pens adjacent to NV+SP pens got infected compared to 1/4 sentinel pigs allocated contiguous to a V+SP pen. These data show that vaccination of piglets significantly decrease parameters related to PRRSV transmission.
authors.affiliation: Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain; Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: emanuela.pileri@cresa.uab.cat.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Pileri
authors.affiliation: Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: elisa.gibert@cresa.uab.cat.
authors.forename: Elisa
authors.initials: E
authors.lastname: Gibert
authors.affiliation: Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: ferransolde@gmail.com.
authors.forename: Ferran
authors.initials: F
authors.lastname: Soldevila
authors.affiliation: Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: ariadna.garcia@cresa.uab.cat.
authors.forename: Ariadna
authors.initials: A
authors.lastname: García-Saenz
authors.affiliation: Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: joan.pujols@cresa.uab.cat.
authors.forename: Joan
authors.initials: J
authors.lastname: Pujols
authors.affiliation: Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: ivan.diaz@cresa.uab.cat.
authors.forename: Ivan
authors.initials: I
authors.lastname: Diaz
authors.affiliation: Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain; Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: laila.darwich@uab.cat.
authors.forename: Laila
authors.initials: L
authors.lastname: Darwich
authors.affiliation: Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain; Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: jordi.casal@uab.cat.
authors.forename: Jordi
authors.initials: J
authors.lastname: Casal
authors.affiliation: Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain; Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: marga.martin@uab.cat.
authors.forename: Marga
authors.initials: M
authors.lastname: Martín
authors.affiliation: Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain; Center de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: enrich.mateu@uab.cat.
authors.forename: Enric
authors.initials: E
authors.lastname: Mateu
mesh_terms: D000281:Administration, Intranasal / Q000662:veterinary; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D005838:Genotype; D008962:Models, Theoretical; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology* / Q000635:transmission / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D013552:Swine; D014611:Vaccination / Q000662:veterinary*; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*; D014766:Viremia / Q000662:veterinary; D017201:Virus Shedding
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines
keywords: Basic reproduction ratio; PRRS virus; Pig; Vaccine