More like “how many BITES would it take for a single vampire to decimate society?” A-one, a-two-who, a-thrrrree? CRUNCH! A-thrrrree.” Actually, according to “experts” Costas Efthimiou and Sohang Gandhi in this linked article, it would take about three years’ worth of bites, provided that the vampires in question feeds once a month. Oxford professor Dino Sejdinović took their study to task, though, for failing to account for the number of vampires that would get staked by humans before they could spread their pestilence. And a study published in APPLIED MATHEMATICAL SCIENCES breaks down the whole conundrum into three categories: The Stoker-King model posits that vampires in the vein (ahem) of Dracula and the revenant in SALEM’S LOT would eliminate all humanity in 165 days; it would take an Anne Rice vampire a bit longer—fifty years; with the TRUE BLOOD variety of vampires, vamps and humans could coexist indefinitely. To me, it all becomes a question of whether or not all victims of vampires become vampires upon death, or if a deliberate action is required on the part of the vampire. If the latter is true, why would a vampire knowingly create competitors for itself?
There’s actually a sound message in these studies, concerning how a group makes use of dwindling resources. There are seven billion “vampires” in the real world, after all, and we’re burning through our world’s reserves faster than we can replenish it.