Many gene editing strategies can be used to produce viral disease-resistant pigs, and these approaches include knock-out or replacement of attachment factors or receptors (heparan sulfate, sialoadhesin, CD163, etc.)involved in viral infection [45–47], and the inhibition of viral replication via the overexpression of antiviral genes (RSAD2, etc.)[48–50]. This evidence concerns the gene RSAD2 and viral load.