title: Immunity raised by recent European subtype 1 PRRSV strains allows better replication of East European subtype 3 PRRSV strain Lena than that raised by an older strain.
abstract: Stable spatial distribution of porcine reproductive and respiratory syndrome (PRRSV)-1 subtypes in Europe is accompanied by a strong population immunity induced by local PRRSV strains. In the present study, it was examined if the immunity induced by three West European subtype 1 PRRSV strains (2007 isolate 07V063 and 2013 isolates 13V091 and 13V117) offers protection against the highly virulent East European subtype 3 PRRSV strain Lena. The number of fever days was greater (p < 0.05) in the control group (7.6 ± 1.7 days) compared to the immune groups (07V063-immune: 4.0 ± 1.2 days, 13V091-immune: 4.6 ± 1.1 days, 13V117-immune: 4.0 ± 2.9 days). In all groups, protection was characterized by reduction (p < 0.05) of AUC values of nasal shedding (control: 14.6, 07V063-immune: 3.4, 13V091-immune: 8.9, 13V117-immune: 8.0) and viremia (control: 28.1, 07V063-immune: 5.4, 13V091-immune: 9.0, 13V117-immune: 8.3). Reduction of respiratory disease, nasal shedding (mean AUC and mean peak values) and viremia (mean AUC and mean peak values) was more pronounced in 07V063-immune (p < 0.05) than in 13V091-immune and 13V117-immune animals. Inoculation with subtype 1 PRRSV strains caused priming of the Lena-specific virus neutralization antibody response. Upon challenge with Lena, we observed a very strong serological booster effect for neutralizing antibodies against strains used for the first inoculation. Our results indicate that inoculation with subtype 1 PRRSV strains can partially protect against antigenically divergent subtype 3 strains. The lower protection level elicited by recently isolated subtype 1 PRRSV strains may impair the outcome of the spatial expansion of subtype 3 strains from East Europe to West Europe.
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. ivan.trus@ugent.be.
authors.forename: Ivan
authors.initials: I
authors.lastname: Trus
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. ilias.frydas@ugent.be.
authors.forename: Ilias S
authors.initials: IS
authors.lastname: Frydas
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. reddy.vishwanatha@ugent.be.
authors.forename: Vishwanatha R A P
authors.initials: VR
authors.lastname: Reddy
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. caroline.bonckaert@ugent.be.
authors.forename: Caroline
authors.initials: C
authors.lastname: Bonckaert
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. yewei.li@ugent.be.
authors.forename: Yewei
authors.initials: Y
authors.lastname: Li
authors.affiliation: National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark. likik@vet.dtu.dk.
authors.forename: Lise K
authors.initials: LK
authors.lastname: Kvisgaard
authors.affiliation: National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark. lael@vet.dtu.dk.
authors.forename: Lars E
authors.initials: LE
authors.lastname: Larsen
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. hans.nauwynck@ugent.be.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Nauwynck
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000918:Antibody Specificity; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology; D010802:Phylogeny; D019318:Porcine Reproductive and Respiratory Syndrome / Q000517:prevention & control*; D019316:Porcine respiratory and reproductive syndrome virus / Q000145:classification* / Q000235:genetics / Q000276:immunology; D013552:Swine; D014765:Viral Vaccines / Q000276:immunology*; D014779:Virus Replication
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D014765:Viral Vaccines