Sorry, "JHU"?

> A viral bioweapon is like trying to enact MAD by being the only ones with nukes and threatening to nuke everyone including yourself unless others do as you wish. It's a domain of mad men.

Maybe I misunderstood you then - you said "the one after that purposeful". Based on your latest comment, I guess this was in relation to small groups or individuals, not governments.

> Contact tracing seems like a no-brainer here. Great payoff for relatively little effort

OK, we have common ground here :) I fully agree that contact tracing is essential when a new and dangerous virus is discovered. Where I think we differ is the means to that end.

Someone with a viral bioweapon will develop it together with a vaccine. They will let only their people and allies have the vaccine, ensuring it is distributed secretly ahead of time, and wipe out everyone else.

Or possibly use it for blackmail: surrender everything to us, and those of you still left alive will be spared.

For context, quoting from Wikipedia:

"The acute toxicity of the compound was demonstrated by the death of heavy metal chemist Karen Wetterhahn, who died 10 months after a single exposure of only a few drops permeated through her disposable latex gloves."

Which reminds me of another, bit more common, chemical: hydrofluoric acid. It's a nasty substance that - in low enough concentration - can penetrate your skin, killing cells on its way to the bones, and disrupt the work of internal organs, with symptoms only visible after hours have passed.

https://en.wikipedia.org/wiki/Hydrofluoric_acid_burn

Not to scare people too much, but the last 100 years have given us a tremendous amount of tools to do harm, a lot of which are available to smart and determined enough individuals. At this point it's evident that the reason humanity hasn't already self-destructed is that most people aren't crazy maniacs and don't want to kill (at least not at random). Bioweapons are particularly nasty here because they self-replicate. It's not like with nuclear weapons, where the limiting factor is that the infrastructure necessary to weaponize fission material is affordable only for state-level actors. For bioweapons, all you need is base pathogen, some (arguably expensive) lab equipment, and a smart enough crazy.