Porcine circovirus 2 (PCV2) is currently considered an important etiologic agent of swine and its infection has potentially serious economic impact on the swine industry worldwide. This virus is frequently associated with postweaning multisystemic wasting syndrome (PMWS), and also with other clinical conditions such as porcine dermatitis and nephropathy syndrome (PDNS), late-term abortions, reproductive failure in sows, proliferative and necrotizing pneumonia and congenital tremors. The term porcine circovirus-associated disease (PCVAD) is currently used to refer to any of these diseases when they are associated with PCV2 infection. The PCV2 was recognized as a pathogen in 1997, and many questions regarding its biology and pathogenesis remain unanswered. Currently, some studies have shown the production of new vaccine candidates and field efficacy testing of commercial vaccines. This review discusses some major points concerned with immunopathogenesis and vaccines for PCV2 infection.
P. D. Lukert, G. F. De Boer, J. L. Dale, P. Keese, M. S. Mcnulty, J. W. Randles and I. Tischer, “The Circoviridae,” In: F. A. Murphy, C. M. Fauquet, D. H. L. Bishop, S. A. Ghabrial, G. P. Martelli and M. A. Mayo, M. D. Summers, Eds., Virus Taxonomy: Six Report of the International Committee on Taxonomy of Viruses, Springer Verlag, New York, 1995, pp. 166-168.
I. Morozov, T. Sirinarumitr, S. D. Sorden, P. G. Halbur, M. K. Morgan, K. J. Yoon and P. S. Paul, “Detection of a Novel Strain of Porcine Circovirus in Pigs with Postweaning Multisystemic Wasting Syndrome,” Journal of Clinical Microbiology, Vol. 36, No. 9, 1998, pp. 2535-2541.
J. Liu, I. Chen, Q. Du, H. Chua and J. Kwang, “The ORF3 Protein of Porcine Circovirus Type 2 Is Involved in Viral Pathogenesis in Vivo,” Journal of Virology, Vol. 80, No. 10, 2006, pp. 5065-5073. doi:10.1128/JVI.80.10.5065-5073.2006
A. K. Karuppannan, M. H. Jong, S.-H Lee, Y. Zhu, M. Selvaraj, J. Lau, Q. Jia and J. Kwang, “Attenuation of Porcine Circovirus 2 in SPF Piglets by Abrogation of ORF3 Function,” Virology, Vol. 383, No. 2, 2009, pp. 338-347. doi:10.1016/j.virol.2008.10.024
I. Tischer, R. Rasch and G. Tochtermann, “Characterization of Papovavirus and Picornavirus-Like Particles in Permanent Pig Kidney Cell Line,” Zentralblatt für Bakteriologie, Vol. 226, No. 2, 1974, pp. 153-167.
J. Segalés, G. M. Allan and M. Domingo, “Porcine Circovirus Diseases,” Animal Health Research Reviews, Vol. 6, No. 2, 2005, pp. 119-142. doi:10.1079/AHR2005106
G. M. Allan and J. A. Ellis, “Porcine Circoviruses: A Review,” Journal of Veterinary Diagnostic Investigation, Vol. 12, No. 1, 2000, pp. 3-14. doi:10.1177/104063870001200102
T. Opriessnig, X. J. Meng and P. G. Halbur, “Porcine Circovirus Type 2 Associated Disease: Update on Current Terminology, Clinical Manifestations, Pathogenesis, Diagnosis, and Intervention Strategies,” Journal of Veterinary Diagnostic Investigation, Vol. 19, No. 6, 2007, pp. 591-615. doi:10.1177/104063870701900601
A. Olvera, M. Cortey and J. Segalés, “Molecular Evolution of Porcine Circovirus Type 2 Genomes: Phylogeny and Clonality,” Virology, Vol. 357, No. 2, 2007, pp. 175-185. doi:10.1016/j.virol.2006.07.047
D. J. An, I. S. Roh, D. S. Song, C. K. Park and B. K. Park, “Phylogenetic Characterization of Porcine Circovirus Type 2 in PMWS and PDNS Korean Pigs between 1999 and 2006,” Virus Research, Vol. 129, No. 2, 2007, pp. 115-122. doi:10.1016/j.virusres.2007.06.024
L. Grau-Roma, E. Crisci, M. Sibila, S. Lopez-Soria, M. Nofrarias, M. Cortey, L. Fraile, A. Olvera and J. Segalés, “A Proposal on Porcine Circovirus Type 2 (PCV2) Genotype Definition and Their Relation with Postweaning Multisystemic Wasting Syndrome (PMWS) Occurrence,” Veterinary Microbiology, Vol. 128, No. 1-2, 2008, pp. 23-35. doi:10.1016/j.vetmic.2007.09.007
O. Chiarelli-Neto, K. S. C. Yotoko, P. M. P. Vidigal, F. M. F. Silva, L. A. Castro, J. L. R. Fietto, A. Silva Jr. and M. R. Almeida, “Classification and Putative Origins of Brazilian Porcine Circovirus 2 Inferred through Phylogenetic and Phylogeographical Approaches,” Virus Research, Vol. 140, No. 1-2, 2009, pp. 57-63. doi:10.1016/j.virusres.2008.11.002
G. M. Allan, S. Kennedy, F. McNeilly, J. C. Foste, J. A. Ellis, S. J. Krakowka, B. M. Meehan and B. M. Adair, “Experimental Reproduction of Severe Wasting Disease by Co-Infection of Pigs with Porcine Circovirus and Porcine Parvovirus,” Journal of Comparative Pathology, Vol. 121, No. 1, 1999, pp. 1-11. doi:10.1053/jcpa.1998.0295
G. M. Rodríguez-Arrioja, J. Segalés, M. Calsamiglia, A. R. Resendes, M. Balasch, J. Plana-Duran, J. Casal and M. Domingo, “Dynamics of Porcine Circovirus Type 2 Infection in a Herd of Pigs with Postweaning Multisystemic Wasting Syndrome,” American Journal of Veterinary Research, Vol. 63, No. 3, 2002, pp. 354-357. doi:10.2460/ajvr.2002.63.354
F. C. Hasslung, M. Berg, G. M. Allan, B. M. Meehan, F. McNeilly and C. Fossum, “Identification of a Sequence from the Genome of Porcine Circovirus Type 2 with an Inhibitory Effect on IFN-α Production by Porcine PBMCs,” J. Gen. Virol., Vol. 84, No. 11, 2003, pp. 2937-2945. doi:10.1099/vir.0.19362-0
H. S. Cho, T. J. Kim, J. I. Lee and N. Y. Park, “Serodiagnostic Comparison of Enzyme-Linked Immunosorbent Assay and Surface Plasmon Resonance for the Detection of Antibody to Porcine Circovirus Type 2,” Canadian Journal of Veterinary Research, Vol. 70, No. 4, 2006, pp. 263-268.
F. Joisel, C. Charreyre, E. Bordin and S. Longo, “Vaccination of Sows and Gilts against PCV2 Diseases: Field Experiences in Europe and Canada,” Proceeding of the XIII Brazilian Congress of Veterinary Specialists in Pigs (ABRAVES), Florianópolis, 26-29 October 2007, pp. 17-29.
J. R. Kolb, “Ingelvac R Circoflex TM Vaccine Against PCV2 Virus,” Proceedings of the XIII Brazilian Congress of Veterinary Specialists in Pigs (ABRAVES), Florianópolis, 26-29 October 2007, pp. 239-245.
M. Fenaux, T. Opriessnig, P. G. Halbur, F. Elvinger and X. J. Meng, “A Chimeric Porcine Circovirus (PCV) with the Immunogenic Capsid Gene of the Pathogenic PCV Type 2 (PCV-2) Cloned into the Genomic Backbone of the Nonpathogenic PCV-1 Induces Protective Immunity against PCV2 Infection in Pigs,” Journal of Virology, Vol. 78, No. 12, 2004, pp. 6297-6303. doi:10.1128/JVI.78.12.6297-6303.2004
S. Ramamoorthy and X. J. Meng, “Porcine Circoviruses: A Minuscule yet Mammoth Paradox,” Animal Health Research Reviews, Vol. 10, No. 1, 2008, pp. 1-20. doi:10.1017/S1466252308001461
J. Segalés, F. Alonso, C. Rosell, J. Pastor, F. Chianini, E. Campos, L. Lopez-Fuertes, J. Quintana, G. RodriguezArrioja, M. Calsamiglia, J. Pujols, J. Dominguez and M. Domingo, “Changes in Peripheral Blood Leukocyte Populations in Pigs with Natural Postweaning Multisystemic Wasting Syndrome (PMWS),” Veterinary Immunology and Immunopathology, Vol. 81, No. 1-2, 2001, pp. 37-44. doi:10.1016/S0165-2427(01)00326-9
L. Darwich, J. Segales, M. Domingo and E. Mateu, “Changes in CD4+, CD8+, CD4+/CD8+, and Immunoglobulin M-Positive Peripheral Blood Mononuclear cells of Postweaning Multisystemic Wasting Syndrome-Affected Pigs Andage-Matched Uninfected Wasted and Healthy Pigs Correlate with Lesions and Porcine Circovirus Type 2 Load in Lymphoid Tissues,” Clinical and Vaccine Immunology, Vol. 9, No. 2, 2002, pp. 236-242. doi:10.1128/CDLI.9.2.236-242.2002
S. S. Grierson, D. P. King, A. W Tucker, M. Donadeu, M. A. Mellencamp, K. Haverson, M. Banks and M. Bailey, “Ontogeny of Systemic Cellular Immunity in the Neonatal Pig: Correlation with the Development of Post-Weaning Multisystemic Wasting Syndrome,” Veterinary Immunology and Immunopathology, Vol. 119, No. 3-4, 2007, pp. 254-268. doi:10.1016/j.vetimm.2007.06.004
W. Sipos, J. C. Duvigneau, M. Willheim, F. Schilcher, R. T. Hartl, G. Hofbauer, B. Exel, P. Pietschmann and F. Schmoll, “Systemic Cytokine Profile in Feeder Pigs Suffering from Natural Postweaning Multisystemic Wasting Syndrome (PMWS) as Determined by Semiquantitative RT-PCR and Flow Cytometric Intracellular Cytokine Detection,” Veterinary Immunology and Immunopathology, Vol. 99, No. 1-2, 2004, pp. 63-71. doi:10.1016/j.vetimm.2004.01.001
J. Nielsen, I. E. Vincent, A. Botner, A. S. LadekaerMikkelsen, G. Allan, A. Summerfield and K. C. McCullough, “Association of Lymphopenia with Porcine Circovirus Type 2 Induced Postweaning Multisystemic Wasting Syndrome (PMWS),” Veterinary Immunology and Immunopathology, Vol. 92, No. 3-4, 2003, pp. 97-111. doi:10.1016/S0165-2427(03)00031-X
P. Meerts, G. Misinzo and H. J. Nauwynck, “Enhancement of Porcine Circovirus 2 Replication in Porcine Cell Lines by IFN-Gamma before and after Treatment and by IFN-α after Treatment,” Journal of Interferon & Cytokine Research, Vol. 25, No. 11, 2005, pp. 684-693. doi:10.1089/jir.2005.25.684
G. Misinzo, P. L. Delputte, D. J. Lefebvre and H. J. Nauwynck, “Increased Yield of Porcine Circovirus-2 by a Combined Treatment of PK-15 Cells with InterferonGamma and Inhibitors of Endosomal Lysosomal System Acidification,” Archives of Virology, Vol. 153, No. 2, 2008, pp. 337-342. doi:1854/10516
I. E. Vincent, C. Balmelli, B. Meehan, G. Allan, A. Summerfield and K. C. McCullough, “Silencing of Natural Interferon Producing Cell Activation by Porcine Circovirus Type 2 DNA,” Immunology, Vol. 120, No. 1, 2007, pp. 47-56. doi:10.1111/j.1365-2567.2006.02476.x
W. Sipos, J. C. Duvigneau, P. Pietschmann, F. Schilcher, G. Hofbauer, R. T. Hartl and F. Schmoll, “Porcine Dermatitis and Nephropathy Syndrome (PDNS) Is Associated with a Systemic Cytokine Expression Profile Indicative of Proinflammation and a Th1 Bias,” Veterinary Immunology and Immunopathology, Vol. 107, No. 3-4, 2005, pp. 303-313. doi:10.1016/j.vetimm.2005.05.003
J. Kim and C. Chae, “Expression of Monocyte Chemoattractant Protein-1 and Macrophage Inflammatory Protein1 in Porcine Circovirus 2-Induced Granulomatous Inflammation,” Journal of Comparative Pathology, Vol. 131, No. 2-3, 2004, pp. 121-126. doi:10.1016/j.jcpa.2004.02.001
G. Sarli, L. Mandrioli, M. Laurenti, L. Sidoli, C. Cerati, G. Rolla and P. S. Marcato, “Immunohistochemical Characterization of the Lymph Node Reaction in Pig PostWeaning Multisystemic Wasting Syndrome (PMWS),” Veterinary Immunology and Immunopathology, Vol. 83, No. 1-2, 2001, pp. 53-67. doi:10.1016/S0165-2427(01)00363-4
M. Kiupel, G. W. Stevenson, E. J. Galbreath, A. North, H. HogenEsch and S. K. Mittal, “Porcine Circovirus Type 2 (PCV2) Causes Apoptosis in Experimentally Inoculated BALB/c Mice,” BMC Veterinary Research, Vol. 1, No. 7, 2005, pp. 1-8.
H. W. Chang, C. R. Jeng, J. J. Liu, T. L. Lin, C. C. Chang, M. Y. Chia, Y. C. Tsai and V. F. Pang, “Reduction of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Infection in Swine Alveolar Macrophages by Porcine Circovirus 2 (PCV2)-Induced Interferon-α,” Veterinary Microbiology, Vol. 108, No. 3-4, 2005, pp. 167-177. doi:10.1016/j.vetmic.2005.03.010
H. W. Chang, C. R. Jeng, T. L. Lin, J. J. Liu, M. Y. Chia, Y. C. Tsai and V. F. Pang, “Immunopathological Effects of Porcine Circovirus Type 2 (PCV2) on Swine Alveolar Macrophages by in Vitro Inoculation,” Veterinary Immunology and Immunopathology, Vol. 110, No. 3-4, 2006, pp. 207-219. doi:10.1016/j.vetimm.2005.09.016
C. Choi and C. Chae, “Distribution of Porcine Parvovirus in Porcine Circovirus 2 Infected Pigs with Postweaning Multisystemic Wasting Syndrome as Shown by in-Situ Hybridization,” Journal of Comparative Pathology, Vol. 123, No. 4, 2000, pp. 302-305. doi:10.1053/jcpa.2000.0421
J. Kim, H. K. Chung, T. Jung, W. S. Cho, C. Choi and C. Chae, “Postweaning Multisystemic Wasting Syndrome of Pigs in Korea: Prevalence, Microscopic Lesions and CoExisting Microorganisms,” Journal of Veterinary Medical Science, Vol. 64, No. 1, 2002, pp. 57-62. doi:10.1292/jvms.64.57
F. J. Pallares, P. G. Halbur, T. Opriessnig, S. D. Sorden, D. Villar, B. H. Janke, M. J. Larson, K. J. Schwartz, K. J. Yoon and L. J. Hoffman, “Porcine Circovirus Type 2 (PCV-2) Coinfections in US Field Cases of Postweaning Multisystemic Wasting Syndrome (PMWS),” Journal of Veterinary Diagnostic Investigation, Vol. 14, No. 6, 2002, pp. 515-519. doi:10.1177/104063870201400614
R. M. Pogranichniy, K. J. Yoon, P. A. Harms, S. D. Sorden and M. Daniels, “Case-Control Study on the Association of Porcine Circovirus Type 2 and other Swine Viral Pathogens with Postweaning Multisystemic Wasting Syndrome,” Journal of Veterinary Diagnostic Investigation, Vol. 14, No. 6, 2002, pp. 449-456. doi:10.1177/104063870201400601
T. Opriessnig, N. E. McKeown, K. L. Harmon, X. J. Meng and P. G. Halbur, “Porcine Circovirus Type 2 Infection Decreases the Efficacy of a Modified Live Porcine Reproductive and Respiratory Syndrome Virus Vaccine,” Clinical and Vaccine Immunology, Vol. 13, No. 8, 2006, pp. 923-929. doi:10.1128/CVI.00074-06
L. T. Fernandes, J. R. Ciacci-Zanella, J. Sobestiansky, M. Schiochet and C. Trombetta, “Coinfeccao Experimental de Circovírus Suíno Tipo 2 (PCV2) Isolado no Brasil e Parvovírus Suíno (PPV) em Auínos SPF,” Arquivo Brasileiro de Medicina Veterinária e Zootecnia, Vol. 58, No. 1, 2006, pp. 1-8. doi:10.1590/S0102-09352006000100001
N. E. McKeown, T. Opriessnig, P. Thomas, D. K. Guenette, F. Elvinger, M. Fenaux, P. G. Halbur and X. J. Meng, “Effects of Porcine Circovirus Type 2 (PCV2) Maternal Antibodies on Experimental Infection of Piglets with PCV2,” Clinical and Vaccine Immunology, Vol. 12, No. 11, 2005, pp. 1347-1351. doi:10.1128/CDLI.12.11.1347-1351.2005
M. Calsamiglia, L. Fraile, A. Espinal, A. Cuxart, C. Seminati, M. Martin, E. Mateu and J. Segalés, “Sow Porcine Circovirus Type-2 (PCV2) Status Effect on Litter Mortality in Post-Weaning Multisystemic Wasting Syndrome (PMWS),” Research in Veterinary Science, Vol. 82, No. 3, 2007, pp. 299-304. doi:10.1016/j.rvsc.2006.08.007
M. Fort, A. Olvera, M. Sibila, J. Segalés and E. Mateu, “Detection of Neutralizing Antibodies in Postweaning Multisystemic Wasting Syndrome (PMWS)-Affected and Non-PMWS-Affected Pigs,” Veterinary Microbiology, Vol. 125, No. 3-4, 2007, pp. 244-255. doi:10.1016/j.vetmic.2007.06.004
R. Larochelle, R. Magar and S. D’Allaire, “Comparative Serologic and Virologic Study of Commercial Swine Herds with and without Postweaning Multisystemic Wasting Syndrome,” Canadian Journal of Veterinary Research, Vol. 67, No. 2, 2003, pp. 114-120.
M. Sibila, M. Calsamiglia, J. Segalés, P. Blanchard, L. Badiella, M. Le Dimna, A. Jestin and M. Domingo, “Use of a Polymerase Chain Reaction Assay and an ELISA to Monitor Porcine Circovirus Type 2 Infection in Pigs from Farms with and without Postweaning Multisystemic Wasting Syndrome,” American Journal of Veterinary Research, Vol. 65, No. 1, 2004, pp. 88-92. doi:10.2460/ajvr.2004.65.88
M. Kixmoller, M. Ritzmann, M. Eddicks, A. Saalmuller, K. Elbersa and V. Fachinger, “Reduction of PMWS-Associated Clinical Signs and Co-Infections by Vaccination against PCV2,” Vaccine, Vol. 26, No. 27-28, 2008, pp. 3443-3451. doi:10.1016/j.vaccine.2008.04.032
M. Fort, M. Sibila, E. Pérez-Martín, M. Nofrarías, E. Mateu and J. Segalés, “One Dose of a Porcine Circovirus 2 (PCV2) Sub-Unit Vaccine Administered to 3-Week-Old Conventional Piglets Elicits Cell-Mediated Immunity and Significantly Reduces PCV2 Viremia in an Experimental Model,” Vaccine, Vol. 27, No. 30, 2009, pp. 4031-4037. doi:10.1016/j.vaccine.2009.04.028
J. B. Hérin, B. Fily, S. Longo and F. Joisel, “Field Results of the Use of Circovac R a Sow PCV2 Vaccine in France under Provisional Registration,” Proceedings of the 5th International Symposium on Emerging and Re-Emerging Pig Diseases, 24-27 June 2007, Krakow, p. 125.
M. Fenaux, T. Opriessnig, P. G. Halbur and X. J. Meng, “Immunogenicity and Pathogenicity of Chimeric Infectious DNA Clones of Pathogenic Porcine Circovirus Type 2 (PCV2) and Nonpathogenic PCV1 in Weanling Pigs,” Journal of Virology, Vol. 77, No. 20, 2003, pp. 11232-11243. doi:10.1128/JVI.77.20.11232-11243.2003
E. C. Doornenbal, “Field Efficacy of Suvaxyn PCV2 one Dose,” Proceedings of the XIII Brazilian Congress of Veterinary Specialists in Pigs (ABRAVES), Florianópolis, 26-29 October 2007, pp. 37-43.
J. Gillespie, N. M. Juhan, J. DiCristina, K. F. Key, S. Ramamoorthy and X. J. Meng, “A Genetically Engineered Chimeric Vaccine against Porcine Circovirus Type 2 (PCV2) Is Genetically Stable in Vitro and in Vivo,” Vaccine, Vol. 26, No. 33, 2008, pp. 4231-4236. doi:10.1016/j.vaccine.2008.05.051
T. Opriessnig, A. R. Patterson, J. Elsener, X. J. Meng and P. G. Halbur, “Influence of Maternal Antibodies on Efficacy of Porcine Circovirus Type 2 (PCV2) Vaccination to Protect Pigs from Experimental Infection with PCV2,” Clinical and Vaccine Immunology, Vol. 15, No. 3, 2008, pp. 397-401. doi:10.1128/CVI.00416-07
H. Fan, C. Ju, T. Tong, H. Huang, J. Lv and H. Chen, “Immunogenicity of Empty Capsids of Porcine Circovius Type 2 Produced in Insect Cells,” Veterinary Research Communications, Vol. 31, No. 4, 2007, pp. 487-496. doi:10.1007/s11259-007-3469-7
F. Boisgérault, G. Moron and C. Leclerc, “Virus-Like Particles: A New Family of Delivery Systems,” Expert Review of Vaccines, Vol. 1, No. 1, 2002, pp. 101-109. doi:10.1586/14760584.1.1.101
P. F. Gerber, G. C. F. Galinari, M. X. Silva, F. S. Campos, A. C. T. Reis and Z. I. P. Lobato, “Distribution of Antibodies against Porcine Circovirus Type-2 (PCV2) in Single Site and Multi-Site Farrow-to-Finish Farms in Brazil,” Research in Veterinary Science, Vol. 87, No. 3, 2009, pp. 488-491.doi:10.1016/j.rvsc.2009.04.013
T. Opriessnig, A. R. Patterson, D. M. Madson, N. Pal and P. G. Halbur, “Comparison of Efficacy of Commercial One Dose and Two Dose PCV2 Vaccines Using a Mixed PRRSV-PCV2-SIV Clinical Infection Model 2-3-Months Post Vaccination,” Vaccine, Vol. 27, No. 7, 2009, pp. 1002-1007. doi:10.1016/j.vaccine.2008.11.105
D. Mahé, P. Blanchard, C. Truong, C. Arnauld, P. Cann, R. Cariolet, F. Madec, E. Albina and A. Jestin, “Differential Recognition of ORF2 Protein from Type 1 and Type 2 Porcine Circoviruses and Identification of Immunorelevant Epitopes,” Journal of General Virology, Vol. 81, No. 7, 2000, pp. 1815-1824.
C. Truong, D. Mahe, P. Blanchard, M. Le Dimna, F. Madec, A. Jestin and E. Albina, “Identification of an Immunorelevant ORF2 Epitope from Porcine Circovirus Type 2 as a Serological Marker for Experimental and Natural Infection,” Archives of Virology, Vol. 146, No. 6, 2001, pp. 1197-1211. doi:10.1007/s007050170115
P. Lekcharoensuk, I. Morozov, P. S. Paul, N. Thangthumniyom, W. Wajjawalku and X. J. Meng, “Epitope Mapping of the Major Capsid Protein of Type 2 Porcine Circovirus (PCV2) by Using Chimeric PCV1 and PCV2,” Journal of Virology, Vol. 78, No. 15, 2004, pp. 8135-8145. doi:10.1128/JVI.78.15.8135-8145.2004
S.-B. Shang, Y.-L. Jin, X.-T. Jianga, J-Y. Zhoua, X. Zhanga, G. Xing, J.-L. He and Y. Yan, “Fine Mapping of Antigenic Epitopes on Capsid Proteins of Porcine Circovirus and Antigenic Phenotype of Porcine Circovirus Type 2,” Molecular Immunology, Vol. 46, No. 3, 2009, pp. 327-334. doi:10.1016/j.molimm.2008.10.028
P. Blanchard, D. Mahé, R. Cariolet, A. Keranflec’h , M. A. Baudouard, P. Cordioli, E. Albina and A. Jestin, “Protection of Swine against Post-Weaning Multisystemic Wasting Syndrome (PMWS) by Porcine Circovirus Type 2 (PCV2) Proteins,” Vaccine, Vol. 21, No. 31, 2003, pp. 4565-4575. doi:10.1016/S0264-410X(03)00503-6
S. Kamstrup, A. M. Barfoed, T. H. Frimann, A. S. Ladekjaer-Mikkelsen and A. Botner, “Immunisation against PCV2 Structural Protein by DNA Vaccination of Mice,” Vaccine, Vol. 22, No. 11-12, 2004, pp.1358-1361. doi:10.1016/j.vaccine.2004.01.032
K. Aravindaram, T.-Y Kuo, C.-W Lan, H.-H Yu, P.-H Wang, Y.-S Chen, G. H.-C. Chen and N.-S Yang, “Protective Immunity against Porcine Circovirus 2 in Mice Induced by a Gene-Based Combination Vaccination,” Journal of Gene Medicine, Vol. 11, No. 4, 2009, pp. 288-301.
A. Silva Jr., L. A. Castro, O. Chiarelli-Neto, F. M. F. Silva, P. M. P. Vidigal, M. P. Moraes and M. R. Almeida, “Development and Evaluation of a Recombinant DNA Vaccine Candidate Expressing Porcine Circovirus 2 Structural Protein,” Pesquisa Veterinária Brasileira, Vol. 29, No. 1, 2009, pp. 76-82. doi:10.1590/S0100-736X2009000100012
H. Shams, “Recent Developments in Veterinary Vaccinology,” Veterinary Journal, Vol. 170, No. 3, 2005, pp. 289-299. doi:10.1016/j.tvjl.2004.07.004
D. E. Hassett, J. Zhang and J. L. Whitton, “Neonatal DNA Immunization with a Plasmid Encoding an Internal Viral Protein Is Effective in the Presence of Maternal Antibodies and Protects against Subsequent Viral Challenge,” Journal of Virology, Vol. 71, No. 10, 1997, pp. 7881-7888.
L. Fischer, S. Barzu, C. Andreoni, N. Buisson, A. Brun and J. C. Audonnet, “DNA Vaccination of Neonate Piglets in the Face of Maternal Immunity Induces Humoral Memory and Protection against a Virulent Pseudorabies Virus Challenge,” Vaccine, Vol. 21, No. 15, 2003, pp. 1732-1741.
J. B. Ulmer, J. C. Sadoff and M. A. Liu, “DNA Vaccines,” Current Opinion in Immunology, Vol. 8, No. 4, 1996, pp. 531-536.
L. A. Babiuk, L.-V Van Drunen, S. Den Hurk, B. I. Loehr and R. Uwiera, “Veterinary Applications of DNA Vaccines,” Developments in Biologicals, Vol. 104, No. 104, 2000, pp. 73-81.
X. Wang, P. Jiang, Y. Li, W. Jiang and X. Dong, “Protection of Pigs against Post-Weaning Multisystemic Wasting Syndrome by a Recombinant Adenovirus Expressing the Capsid Protein of Porcine Circovirus Type 2,” Veterinary Microbiology, Vol. 121, No. 3-4, 2007, pp. 215-224. doi:10.1016/j.vetmic.2006.11.027
Z. Feng, P. Jiang, X. Wang, Y. Li and W. Jiang, “Adenovirus-Mediated shRNA Interference against Porcine Circovirus Type 2 Replication both in Vitro and in Vivo,” Antiviral Research, Vol. 77, No. 3, 2008, pp. 186-194.
F. Tashiro, H. Niwa and J. I. Miyazaki, “Constructing Adenoviral Vectors by Using the Circular Form of the Adenoviral Genome Cloned in a Cosmid and the CreLoxp Recombinant System,” Human Gene Therapy, Vol. 10, No. 11, 1999, pp. 1845-1852. doi:10.1089/10430349950017527
M. Lusky, M. Christ, K. Rittner, A. Dierterlr, D. Dreyer, B. Mourot, H. Schultz, F. Stoeckel, A. Pavirani and M. Mehtali, “In Vitro and in Vivo Biology of Recombinant Adenovirus Vectors with E1, E1/E2A, or E1/E4 Deleted,” Journal of Virology, Vol. 72, No. 3, 1998, pp. 1396-1405.
J. W. Moorhead, G. H. Clayton, R. L. Smith and J. Schaack, “A Replication-Incompetent Adenovirus Vector with the Preterminal Protein Gene Deleted Efficiently Transduces Mouses Ears,” Journal of Virology, Vol. 73, No. 2, 1999, pp. 1046-1053.
O. Chiarelli-Neto, “Caracterizacao Imunológica de um Adenovírus Recombinante que Expressa a Proteína do Capsídeo do Circovírus Suíno 2,” Mastet’s Thesis, Federal University of Vicosa, Vicosa, 2009.
C. Ju, H. Fan, Y. Tan, Z. Liu, X. Xi, S. Cao, B. Wu and H. Chen, “Immunogenicity of a Recombinant Pseudorabies Virus Expressing ORF1-ORF2 Fusion Protein of Porcine Circovirus Type 2,” Veterinary Microbiology, Vol. 109, No. 3-4, 2005, pp. 179-190. doi:10.1016/j.vetmic.2005.06.001
Y. Song, M. Jin, S. Zhang, X. Xu, S. Xiao, S. Cao and H. Chen, “Generation and Immunogenicity of a Recombinant Pseudorabies Virus Expressing Cap Protein of Porcine Circovirus Type 2,” Veterinary Microbiology, Vol. 119, No. 2-4, 2007, pp. 97-104. doi:10.1016/j.vetmic.2006.08.026
L. E. Pomeranz, A. E. Reynolds and C. J. Hengartner, “Molecular Biology of Pseudorabies Virus: Impact on Neurovirology and Veterinary Medicine,” Microbiology and Molecular Biology Reviews, Vol. 69, No. 3, 2005, pp. 462-500. doi:10.1128/MMBR.69.3.462-500.2005
M. Van zijl, L. G. Wensvoort, E. De kluyver, M. Huls, H. Van der Gulden, A. Gielkens, A. Berns, I. E. Vincent, C. Balmelli, B. Meehan, G. Allan, A. Summerfield and K. C. McCullough, “Silencing of Natural Interferon Producing Cell Activation by Porcine Circovirus Type 2 DNA,” Immunology, Vol. 120, No. 1, 2007, pp. 47-56. doi:10.1111/j.1365-2567.2006.02476.x
K. Wang, L. Huang, J. Kong and X. Zhang, “Expression of the Capsid Protein of Porcine Circovirus Type 2 in Lactococcus lactis for Oral Vaccination,” Journal of Virological Methods, Vol. 150, No. 1-2, 2008, pp. 1-6. doi:10.1016/j.jviromet.2008.02.014
S. Drouault, G. Corthier, S. D. Ehrlich and P. Renault, “Survival, Physiology, and Lysis of Lactococcus lactis in the Digestive Tract,” Applied and Environmental Microbiology, Vol. 65, No. 11, 1999, pp. 4881-4886.