I liked this comment from Rudolf Winestock
The plague that will wipe out most of humanity won’t be some super pathogen that’s immune to modern pharmacology, it’ll be an easy-to-treat pathogen so situated in the vector/target space that dealing with it rationally would make politically powerful groups howl.
A post from Gregory Cochran's and Henry Harpending's excellent blog West Hunter.
The commenter Ron Pavellas adds:
The Wasserman Test.