Evaluation of novel recombinant porcine circovirus type 2d (PCV2d) vaccine in pigs naturally infected with PCV2d

• Published in: Vaccine Vol. 39; no. 3; pp. 529 - 535
• Main Authors: Kim, Kiju, Hahn, Tae-Wook
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 15.01.2021; Elsevier Limited
• Subjects: Allergy and Immunology; Amino acids; Animals; Antibodies; Antibodies, Viral; Baculoviridae; Baculovirus; Capsid protein; Circoviridae Infections - prevention & control; Circoviridae Infections - veterinary; Circovirus - genetics; coat proteins; Commercial farms; Deoxyribonucleic acid; DNA; Economic impact; genotype; Genotype & phenotype; Genotypes; Hogs; Immune response; Immunization; Immunoglobulin G; Infections; Interleukin 4; Laboratories; maternal immunity; Monoclonal antibodies; neutralizing antibodies; PCV2d vaccine; Porcine circovirus type 2 (PCV2); Porcine circovirus-2; Proteins; recombinant antigens; Recombinant baculovirus; recombinant proteins; recombinant vaccines; subunit vaccines; Swine; Swine Diseases - prevention & control; Swine production; vaccination; Vaccines; Viral Vaccines; Viremia; Virus-like particle (VLP); Viruses; Denmark; United States > US; China; Virus-like particle (VLP); Recombinant baculovirus; Capsid protein; Porcine circovirus type 2 (PCV2); PCV2d vaccine
• ISSN: 0264-410X; 1873-2518; 1873-2518
• DOI: 10.1016/j.vaccine.2020.12.013

•PCV2b- and PCV2d-based virus-like particles (VLPs) were successfully generated.•This VLPs induced highly neutralizing antibodies in pigs naturally infected with PCV2d.•Interestingly, PCV2d viremia level was significantly reduced in the Bac-2dCP group.•The Bac-2dCP protein is a potential vaccine candidate for prevent against PCV2d. The pathogenic porcine circovirus type 2 (PCV2) causes significant economic losses in pig production. Emergence of the PCV2d genotype has been linked with PCV2-associated disease (PCVAD) outbreaks. However, no study has been conducted efficacy of an experimental PCV2d-based subunit vaccine in pigs. Therefore, PCV2b- and PCV2d-based capsid (CP) proteins were generated using a baculovirus (Bac) expression system, and we evaluated the protective immune responses in a commercial pig farm where predominant PCV2d is circulating. Eighteen 3-week-old pigs with maternal antibodies were randomly divided into four groups, and were immunized with purified Bac-2dCP, mixed 1:1 ratio with purified Bac-2bCP and Bac-2dCP (Bac-mCP), a commercial PCV2a-based subunit vaccine (VAC) or phosphate-buffered saline (PBS) as controls. The Bac-2dCP and Bac-mCP groups had significantly higher PCV2b- or PCV2d- specific IgG and neutralizing antibody without interference by maternal antibody compared to control group in pigs naturally infected with PCV2d. Interestingly, not only serum IL-4 level was significantly increased in the Bac-2dCP group, but also PCV2d viremia level was significantly reduced than the control group. The recombinant Bac-2dCP subunit vaccine is a good candidate for the effective reduction against PCV2d infection.