| abstract |
The present invention relates to infectious DNA clones of porcine circoviruses (PCVs), infectious chimeric DNA clones, vaccines, and means of protecting pigs from swine swine systemic atrophy syndrome (PMWS) or viral infections caused by PCV2. The novel chimeric infectious DNA clones and their derived, pathogenic chimeric viruses are constructed from nonpathogenic PCV1 in which the immunogenic ORF gene of pathogenic PCV2 replaces the gene of nonpathogenic PCV1, preferably at the same location. Chimeric viruses advantageously maintain the nonpathogenic phenotype of PCV1, but induce specific immune responses against pathogenic PCV2. The present invention further includes immunogenic polypeptide expression products. |