AFRICAN SWINE FEVER VIRUS VACCINE STRAIN ASFV-G-dI177L SERIAL PASSAGING IN PIGS

ASFV-G-dI177L is a gene-deleted modified-live African swine fever virus (ASFV) vaccine strain that is incorporated in a commercially available vaccine to combat a devastating swine disease. As there are inherent safety risk associated with ASFV vaccine strains, we sought to investigate the safety of ASFV-G-dI177L in pregnant sows and its genetic stability in an in vivo passaging experiment. It was observed in the in vivo passaging experiments that ASFV-G-dI177L reverted to virulence, based on increasing levels of ASF-specific clinical scores upon passaging with severe ASF-specific clinical signs in passage 3 and 4.