title: Modified-live PRRSV subtype 1 vaccine UNISTRAIN®PRRS provides a partial clinical and virological protection upon challenge with East European subtype 3 PRRSV strain Lena.
abstract: BACKGROUND
  Western European porcine reproductive and respiratory syndrome virus (PRRSV) strains cause limited and mild clinical signs whereas more virulent strains are circulating in Eastern Europe. The emergence of such highly virulent strains in Western Europe might result in severe clinical problems and a financial disaster. In this context, the efficacy of the commercial modified-live PRRSV subtype 1 vaccine UNISTRAIN®PRRS was tested upon challenge with the East European subtype 3 PRRSV strain Lena.
  
  
  RESULTS
  The mean duration of fever was shortened and the number of fever days was significantly lower in vaccinated pigs than in control pigs. Moreover, a lower number of vaccinated animals showed fever, respiratory disorders and conjunctivitis. The mean virus titers in the nasal secretions post challenge (AUC) were significantly lower in the vaccinated group than in the control group. The duration of viremia was slightly shorter (not significantly different) in the vaccinated group as compared to the control group.
  
  
  CONCLUSIONS
  Vaccination of pigs with the modified-live vaccine UNISTRAIN®PRRS provides a partial clinical and virological protection against the PRRSV subtype 3 strain Lena.
authors.affiliation: Laboratory of Virology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
authors.forename: Caroline
authors.initials: C
authors.lastname: Bonckaert
authors.affiliation: Laboratory of Virology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
authors.forename: Karen
authors.initials: K
authors.lastname: van der Meulen
authors.affiliation: Laboratorios Hipra S.A., Amer (Girona), Spain.
authors.forename: Isaac
authors.initials: I
authors.lastname: Rodríguez-Ballarà
authors.affiliation: Laboratorios Hipra S.A., Amer (Girona), Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Pedrazuela Sanz
authors.affiliation: Laboratorios Hipra S.A., Amer (Girona), Spain.
authors.forename: Mar Fenech
authors.initials: MF
authors.lastname: Martinez
authors.affiliation: Laboratory of Virology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Nauwynck
keywords: Modified-live; PRRSV; Protection; UNISTRAIN® PRRS; Vaccine; subtype 1; subtype 3 Lena