What if, in the future, all of us are receive a vaccine made from a chimera virus? A virus that could not have ever evolved on its own?
Take the most infectious, most virulent, most deadly. Make a vaccine out of it.
Then this virus is used as a vaccine. Some governments use it as a precursor for biological weapons… which obviously don’t work as everyone on the planet receives the vaccine even if you were not injected with it. The virus infects everyone on the planet.
A few million die… but the rest are guaranteed to never develop cancer in their lifetimes.
It’s the stuff of science fiction, made reality. I’ve only read one story that makes use of this argument and sadly, I’ve forgotten the name of it. It involves a mermaid and her lover, whom has come to find her after he died.