Deriving a "lethal bit count" from virus genomes is not quite fair, since the virus requires considerable metabolic support from the host genome. I think I can

Deriving a "lethal bit count" from virus genomes is not quite fair, since the virus requires considerable metabolic support from the host genome. I think I can kill you with 21 bits: hydrogen cyanide is a three-atom molecule. Assume 128 chemical elements --> 7 bits per atom. And the molecule will assemble itself from the constituent atoms, so no extra information is needed for that. Hydrogen fluoride might work, too: 14 bits. And, of course, a slug of plutonium would kill you both chemically (poison) and radioactively: 7 bits. Can't do better than that. Oh wait, if I shot a stream of electrons at you, that could kill you, too. There are six types of leptons (ignoring anti-matter), so that's three bits.