A genetically engineered chimeric vaccine against porcine circovirus type 2 (PCV2) is genetically stable in vitro and in vivo

作者：Gillespie J; Juhan N M; DiCristina J; Key K F; Ramamoorthy S; Meng X J^*

来源：Vaccine, 2008, 26(33): 4231-4236.

DOI：10.1016/j.vaccine.2008.05.051

• porcine circovirus type 2 (PCV2)
• porcine circovirus-associated disease (PCVAD)
• vaccine
• genetic stability

A vaccine against porcine circovirus type 2 (PCV2), designated PCV1-2 chimera, was recently developed by replacing the capsid gene of the non-pathogenic PCV1 with that of PCV2. The PCV1-2 chimera Virus is attenuated in pigs but induces protective immunity against PCV2. In this study, the genetic stability of the PCV1-2 chimera was evaluated for its potential use as a live vaccine. The PCV1-2 chimera virus was serially passaged 11 times in PK-15 cells and 3 times in pigs. The PCV1-2 chimera virus used in this study contained a tracking market mutation in the capsid gene (F to V at amino acid position 79). Sequence analyses of the PCV1-2 chimera virus after 11 serial passages in PK-15 cells did not reveal any sequence change including the marker mutation. Similarly, there is no change in the genomic sequence of the PCV1-2 chimera virus recovered from pigs during 3 serial in vivo passages. Under in vivo selection pressure, however, the introduced tracking marker mutation in the PCV1-2 chimera quickly mutated (V79F) and restored to its original sequence after one passage in pigs, and remained stable in subsequent 2 passages in pigs. The results indicate that the PCV1-2 chimera virus is genetically stable, and thus should be a good vaccine candidate.

• 出版日期2008-8-5