Mutations of the PCV-2 capsid motif, specific of each PCV-2 genogroup, attenuate virulence in vivo

After the re-emergence of PMWS in North America in 2005, the presence of new circulating PCV-2 isolates belonging to PCV-2b genogroup raises the assumption that this genogroup is more virulent than the PCV-2a one. Viruses of each genogroup contain a distinct motif of amino acid in the capsid protein (amino acids 86 to 91), the unique component of the virus outer structure1. In this study, we investigate if PCV-2 genetic variation is responsible of virulence and check if the capsid motif contributes to this difference.