PMID- 21951266 OWN - NLM STAT- MEDLINE DCOM- 20120712 LR - 20120103 IS - 1348-0421 (Electronic) IS - 0385-5600 (Linking) VI - 55 IP - 12 DP - 2011 Dec TI - An experimental live chimeric porcine circovirus 1-2a vaccine decreases porcine circovirus 2b viremia when administered intramuscularly or orally in a porcine circovirus 2b and porcine reproductive and respiratory syndrome virus dual-challenge model. PG - 863-73 LID - 10.1111/j.1348-0421.2011.00385.x [doi] AB - Commercially available inactivated vaccines against porcine circovirus type 2 (PCV2) have been shown to be effective in reducing PCV2 viremia. Live-attenuated, orally administered vaccines are widely used in the swine industry for several pathogens because of their ease of use yet they are not currently available for PCV2 and efficacy. The aims of this study were to determine the efficacy of a live-attenuated chimeric PCV2 vaccine in a dual-challenge model using PCV2b and porcine reproductive and respiratory syndrome virus (PRRSV) and to compare intramuscular (IM) and oral (PO) routes of vaccination. Eighty-three 2-week-old pigs were randomized into 12 treatment groups: four vaccinated IM, four vaccinated PO and four non-vaccinated (control) groups. Vaccination was performed at 3 weeks of age using a PCV1-2a live-attenuated vaccine followed by no challenge, or challenge with PCV2b, PRRSV or a combination of PCV2b and PRRSV at 7 weeks of age. IM administration of the vaccine elicited an anti-PCV2 antibody response between 14 and 28 days post vaccination, 21/28 of the pigs being seropositive prior to challenge. In contrast, the anti-PCV2 antibody response in PO vaccinated pigs was delayed, only 1/27 of the pigs being seropositive at challenge. At 21 days post challenge, PCV2 DNA loads were reduced by 80.4% in the IM vaccinated groups and by 29.6% in the PO vaccinated groups. PCV1-2a (vaccine) viremia was not identified in any of the pigs. Under the conditions of this study, the live attenuated PCV1-2a vaccine was safe and provided immune protection resulting in reduction of viremia. The IM route provided the most effective protection. CI - (c) 2011 The Societies and Blackwell Publishing Asia Pty Ltd. FAU - Opriessnig, Tanja AU - Opriessnig T AD - Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa 50011, USA. tanjaopr@iastate.edu FAU - Gomes-Neto, Joao C AU - Gomes-Neto JC FAU - Hemann, Michelle AU - Hemann M FAU - Shen, Hui-Gang AU - Shen HG FAU - Beach, Nathan M AU - Beach NM FAU - Huang, Yaowei AU - Huang Y FAU - Halbur, Patrick G AU - Halbur PG FAU - Meng, Xiang-Jin AU - Meng XJ LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - Australia TA - Microbiol Immunol JT - Microbiology and immunology JID - 7703966 RN - 0 (Antibodies, Viral) RN - 0 (DNA, Viral) RN - 0 (RNA, Viral) RN - 0 (Vaccines, Attenuated) RN - 0 (Vaccines, Subunit) RN - 0 (Viral Vaccines) SB - IM MH - Administration, Oral MH - Animals MH - Antibodies, Viral/blood MH - Chimera MH - Circoviridae Infections/immunology/prevention & control/*veterinary MH - Circovirus/genetics/*immunology MH - Coinfection MH - DNA, Viral/blood MH - Injections, Intramuscular MH - Porcine Reproductive and Respiratory Syndrome/immunology/*prevention & control/virology MH - Porcine respiratory and reproductive syndrome virus/genetics/*immunology MH - RNA, Viral/blood MH - Random Allocation MH - Specific Pathogen-Free Organisms MH - Swine MH - Swine Diseases/immunology/*prevention & control/virology MH - Vaccination/veterinary MH - Vaccines, Attenuated/administration & dosage MH - Vaccines, Subunit/administration & dosage MH - Viral Vaccines/*administration & dosage MH - Weight Gain EDAT- 2011/09/29 06:00 MHDA- 2012/07/13 06:00 CRDT- 2011/09/29 06:00 PHST- 2011/09/29 06:00 [entrez] PHST- 2011/09/29 06:00 [pubmed] PHST- 2012/07/13 06:00 [medline] AID - 10.1111/j.1348-0421.2011.00385.x [doi] PST - ppublish SO - Microbiol Immunol. 2011 Dec;55(12):863-73. doi: 10.1111/j.1348-0421.2011.00385.x.