Of the survivors children it kills a quarter. Afterward it s a childhood disease. Historians aren t interested writing it down when everyone around them is dying. Pasteur and Lister rewrote the future forever. Sure they did, but the tiny life forms are catching up.
Staph infections mutate faster than doctors or sulfa drugs.
Natural diseases are bad enough, but we know the shape of DNA now. Biological war is way cheaper than thermonuclear bombs and way harder to trace. Business can be done over the net without jet lag, without facing local preferences in body odor, bed size, alcohol or tobacco or local cuisine. Okay, but we can date over the net before we get physical. We can learn a little.