Deletion of the African swine fever virus gen I196L in the Georgia2010 isolate genome does not affect virus replication or virulence in domestic pigs.

Authors: Borca, Manuel; Ramirez Medina, Elizabeth; MUTISYA, CHRISTINE - International Livestock Research Institute (ILRI) - Kenya; OJUOK, ROSE - International Livestock Research Institute (ILRI) - Kenya; ODABA, JOSIAH - International Livestock Research Institute (ILRI) - Kenya; DIHBOL, MARK - US Department Of Agriculture (USDA); Gladue, Douglas

Submitted to: Vaccines
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2025
Publication Date: 4/23/2025
Citation: Borca, M.V., Ramirez Medina, E., Mutisya, C., Ojuok, R., Odaba, J., Dihbol, M., Gladue, D.P. 2025. Deletion of the African swine fever virus gen I196L in the Georgia2010 isolate genome does not affect virus replication or virulence in domestic pigs. Vaccines. 17(5):603. https://doi.org/10.3390/v17050603.
DOI: https://doi.org/10.3390/v17050603

Interpretive Summary: The manuscript describes the presence of cross protection induced by a live attenuated ASFV vaccine developed by ARS against different virulent field strains which are genotipically distant from the vaccine strain. Data demonstrated that there is a correlation in the genetic differences among the strain tested and the results obtained in protection.

Technical Abstract: Vaccine development for the prevention of ASF has been very challenging. Inactivated vaccines, using different types of inactivation methodologies as well as a variety of adju-vants have been consistently inefficacious. Historically, animals recovering from an infec-tion with an attenuated virus strain became protected to the development of a clinical disease caused by an antigenically related strain. Therefore, immunization of susceptible animals with attenuated virus strains has become a common method of vaccination, in fact, the two first commercial vaccines approved to be used in field conditions are based on recombinant viruses obtained by this approach. An important limitation is that the efficacy of the LAV is restricted to those virus strains that are antigenically related and, in most of the cases, these recombinant strains provide protection only against their parental virulent strain. This is a critical issue since the large genetic and antigenic heterogeneity among all ASFV field isolates making the development of vaccines which can be widely used in different geographical areas harboring different isolates a challenge. Besides the anecdotal data, there is not a large amount of information describing patterns of cross-protection between different ASFV strains. In this study we evaluated the cross-protection induced by the of ASFV live-attenuated vaccine ASFV-G-dI177L against the different biotypes of ASFV and compared the genomic sequences to determine poten-tial genetic mutations that could cause the lack of cross protection.