Reduction of porcine circovirus type 2 (PCV2) viremia by a reformulated inactivated chimeric PCV1-2 vaccine-induced humoral and cellular immunity after experimental PCV2 challenge

BMC Veterinary Research. 2012;8(1):194 DOI 10.1186/1746-6148-8-194

 

Journal Homepage

Journal Title: BMC Veterinary Research

ISSN: 1746-6148 (Online)

Publisher: BMC

LCC Subject Category: Agriculture: Animal culture: Veterinary medicine

Country of publisher: United Kingdom

Language of fulltext: English

Full-text formats available: PDF, HTML

 

AUTHORS

Seo Hwi
Oh Yeonsu
Han Kiwon
Park Changhoon
Chae Chanhee

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 22 weeks

 

Abstract | Full Text

<p>Abstract</p> <p>Background</p> <p>The objective of the present study was to elucidate the humoral and cellular immune response mechanisms by which a reformulated inactivated chimeric PCV1-2 vaccine reduces the PCV2 viremia. Forty PCV2 seronegative 3-week-old pigs were randomly divided into the following four groups: vaccinated challenged (T01), vaccinated non-challenged (T02), non-vaccinated challenged (T03), and non-vaccinated non-challenged (T04) animals. The pigs in groups T01 and T02 were immunized with a reformulated inactivated chimeric PCV1-2 vaccine (Fostera™ PCV; Pfizer Animal Health) administered as a 2.0 ml dose at 21 days of age. At 35 days of age (0 days post-challenge), the pigs in groups T01 and T03 were inoculated intranasally with 2 ml each of PCV2b.</p> <p>Results</p> <p>A reduction of PCV2 viremia coincided with the appearance of both PCV2-specific neutralizing antibodies (NA) and interferon-γ-secreting cells (IFN-γ-SCs) in the vaccinated animals. However, the presence of anti-PCV2 IgG antibodies did not correlate with the reduction of PCV2 viremia. Lymphocyte subset analysis indicated that the numbers of CD3<sup>+</sup> and CD4<sup>+</sup> cells increased in vaccinated animals but the numbers of CD4<sup>+</sup> cells decreased transiently in non-vaccinated animals. The observation of a delayed type hypersensitivity response in only the vaccinated animals also supports a CD4<sup>+</sup> cell-associated protective cellular immune response induced by the reformulated inactivated chimeric PCV1-2 vaccine.</p> <p>Conclusions</p> <p>The induction of PCV2-specific NA and IFN-γ-SCs, and CD4<sup>+</sup> cells by the reformulated inactivated chimeric PCV1-2 vaccine is the important protective immune response leading to reduction of the PCV2 viremia and control of the PCV2 infection. To our knowledge this is the first demonstration of protective humoral and cellular immunity induced by the reformulated inactivated chimeric PCV1-2 vaccine and its effect on reduction of PCV2 viremia by vaccination.</p>