The Giving Plague
by David Brin
Yeah, you viruses need vectors, don’t you. I mean, if you kill a guy, you’ve got to have a life raft, so you can desert the ship you’ve sunk, so you can cross over to some new hapless victim. Same applies if the host proves tough, and fights you off — gotta move on. Always movin’ on.
Hell, even if you’ve made peace with a human body, like Les suggested, you still want to spread, don’t you? Big-time colonizers, you tiny beasties.
Oh, I know. It’s just natural selection. Those bugs that accidentally find a good vector spread. Those that don’t, don’t. But it’s so eerie. Sometimes it sure feels purposeful…