title: Antibody responses following vaccination versus infection in a porcine circovirus-type 2 (PCV2) disease model show distinct differences in virus neutralization and epitope recognition.
abstract: Porcine circovirus associated disease (PCVAD) encompasses a group of syndromes linked to infection with porcine circovirus type 2 (PCV2). Based on the hypothesis that the immune responses to vaccination versus infection are quantitatively and qualitatively different, the objective of this study was to evaluate immunity, virus replication and disease protection in pigs vaccinated with PCV2 capsid protein (CP) and during infection. The disease model included dual infection with PCV2 and porcine reproductive and respiratory syndrome virus (PRRSV), a virus known to enhance disease progression and severity. The principal effect of PRRSV infection was to increase peak PCV2 viremia by almost 40-fold; however, PCV2 failed to show a reciprocal effect on PRRSV. In vaccinated pigs, there was no evidence of disease or PCV2 replication following dual virus challenge. Immunity following vaccination favored PCV2 neutralizing activity; whereas, PCV2 infection and disease produced high levels of non-neutralizing antibody, primarily directed against a polypeptide in the C-terminal region of CP. These results support the notion that the magnitude of the total antibody response cannot be used as a measure of protective immunity. Furthermore, protection versus disease lies in the immunodominance of specific epitopes. Epitope specificity should be taken into consideration when designing PCV2 vaccines.
authors.affiliation: Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, 1800 Denison Ave, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Trible
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ramirez
authors.forename: Andrew
authors.initials: A
authors.lastname: Suddith
authors.forename: Alexandra
authors.initials: A
authors.lastname: Fuller
authors.forename: Maureen
authors.initials: M
authors.lastname: Kerrigan
authors.forename: Richard
authors.initials: R
authors.lastname: Hesse
authors.forename: Jerome
authors.initials: J
authors.lastname: Nietfeld
authors.forename: Baoqing
authors.initials: B
authors.lastname: Guo
authors.forename: Eileen
authors.initials: E
authors.lastname: Thacker
authors.forename: Raymond R R
authors.initials: RR
authors.lastname: Rowland
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood*; D000914:Antibodies, Viral / Q000097:blood*; D018173:Circoviridae Infections / Q000276:immunology* / Q000821:virology; D017925:Circovirus / Q000145:classification / Q000235:genetics / Q000276:immunology*; D060085:Coinfection / Q000276:immunology / Q000821:virology; D004195:Disease Models, Animal; D000939:Epitopes / Q000276:immunology; D008969:Molecular Sequence Data; D019316:Porcine respiratory and reproductive syndrome virus / Q000472:pathogenicity; D017422:Sequence Analysis, DNA; D013552:Swine; D019562:Viral Load; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014766:Viremia / Q000175:diagnosis / Q000821:virology
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000939:Epitopes; D014765:Viral Vaccines