"the mutated virus would have a survival advantage of not killing its host." Not terribly reassuring :) Perhaps 1918 wasn't a very high-fitness virus, but it s

"the mutated virus would have a survival advantage of not killing its host." Not terribly reassuring :) Perhaps 1918 wasn't a very high-fitness virus, but it still got ~5% of us before burning out. That leaves the threat level >> (conventional) terrorism.