title: Evaluation of natural porcine circovirus type 2 (PCV2) subclinical infection and seroconversion dynamics in piglets vaccinated at different ages.
abstract: This study aimed to determine the porcine circovirus type 2 (PCV2) serological and virological dynamics in piglets vaccinated at different ages in a PCV2 subclinical infection (PCV2-SI) scenario. Six hundred and forty-four 2 week-old healthy piglets were selected and distributed into four treatment groups: vaccination at 3, 6 or 10 weeks of age (3W-VAC, 6W-VAC and 10W-VAC groups, respectively) and unvaccinated pigs (NON-VAC group). Blood (n = 112 pigs) and oral fluid (OF) (n = 40 pens) samples were taken throughout the study to assess PCV2 load, humoral immunity and viral genotyping. Percentage of PCV2-DNA positive sera mainly raised by 10 weeks of age, being maximum at 14 weeks of age, and then started to decrease at 18 and 25 weeks of age. Specifically, PCV2 vaccination at 3 or 6 weeks of age yielded similar results, since they produced an earlier seroconversion and reduced, at different sampling points, the proportion of viremic animals in comparison to the unvaccinated group. In contrast, PCV2 vaccination at 10 weeks of age only achieved such reduction at 25 weeks of age; in this case, vaccination coincided with the increase of the percentage of viremic pigs in the population. Both serological techniques used in sera and OF offered similar results with a high and statistically significant correlation. In contrast, a higher percentage of PCV2 DNA positivity was detected in OF in comparison with sera. In conclusion, under the present study conditions, the optimal time for PCV2 piglet vaccination was at either 3 or 6 weeks of age.
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.|Merial Laboratorios, 08014, Barcelona, Spain.
authors.forename: Salvador
authors.initials: S
authors.lastname: Oliver-Ferrando
authors.affiliation: UAB, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.|Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, UAB, 08193, Bellaterra, Spain.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Segalés
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: López-Soria
authors.affiliation: Merial Laboratorios, 08014, Barcelona, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Callén
authors.affiliation: Merial S.A.S., 69007, Lyon, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Merdy
authors.affiliation: Merial S.A.S., 69007, Lyon, France.
authors.forename: François
authors.initials: F
authors.lastname: Joisel
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain. marina.sibila@irta.cat.
authors.forename: Marina
authors.initials: M
authors.lastname: Sibila
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn / Q000276:immunology / Q000821:virology; D058345:Asymptomatic Infections; D018173:Circoviridae Infections / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000276:immunology; D005260:Female; D008297:Male; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control / Q000821:virology*; D014765:Viral Vaccines / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D014765:Viral Vaccines