I seem to recall that without viruses there would be no life as we know it. They are just another stage on from fungi and bacteria and all the other so say nasties that are the building blocks of life on earth.
Discussion
Right, those things usually presented to be viruses that come from outside the body, in reality are exosomes (extracellular vesicles) produced by the body itself. And they indeed can transform into either fungi or bacteria depending on the bodies needs. These things in reality are just the firefighters (the good guys) that just happen to be at the place of a fire, but that does not mean that they caused it (there is absolutely zero evidence for that).