Biting is a ridiculous way to spread a virus, you know. Truly stupid. Just think about that for a moment.
Seems to work pretty well for rabies. Almost *any* mammal can harbor & spread rabies. Deer, cattle, orca whales. Imagine getting rabies from an orca that ate a rabid moose.
Malaria spreads through mosquito bites. Tick-borne illnesses are spread by tick bites.

