Johny Thundersbeard does not procrastinate about writing
“This is an awesome idea for a story.”
Maybe it doesn’t kill people, but acts in a symbiotic/parasitic manner giving super intelligence and coherence to animals.
Or, it gives immortality to humans but like mummies rather then zombies, you cannot die no matter what happens, you keep rotting and ageing though.
Or, it gives healing powers to people. It eats other diseases like cancer. But at what cost?
Add your own writing prompts about rediscovered virii in the Comments….