Both viruses and bacteria cause disease; pathogenic viruses aren’t naturally created in the body as a response to damage
Pathogenic viruses and bacteria cause infectious diseases and, for both of these microbes to cause a disease, they first have to be caught, they are not generated spontaneously inside one’s body. In the case of viruses, these microbes infect cells and replicate inside them, using the cell’s machinery to produce more copies of the pathogenic virus that can leave the infected cells and infect new cells and also new individuals.