CRISPR/Cas9 editing of genotype IX African swine fever virus

African swine fever virus (ASFV) is the etiological agent of a contagious and fatal disease of domestic pigs that has significant economic consequences for the global swine industry. Due to the lack of effective treatment and vaccines against African swine fever, there is an urgent need to leverage cutting-edge technologies and cost-effective approaches for generating and purifying recombinant virus to fast-track the development of live-attenuated ASFV vaccines. Here, we use the CRISPR/Cas9 gene editing system to produce recombinant ASFVs. We developed a recombinant virus lacking the non-essential gene A238L (5EL) in the highly virulent genotype IX ASFV (Kenya 1033) genome.