Of all the sentient populations inhabiting Earth, humans make up the largest populace on the planet. The vast majority of humans on Earth do not believe in the supernatural, and do not have any idea that supernatural beings like vampires, werewolves, alraune, skeletons, scyllas and others exist among them.
Rather than portray humans as completely helpless against such beings, Vamp! creator Ryohgo Narita turns the typical vampire-human predator-prey relationship on its head. In the Naritaverse, humans can become stronger by consuming the blood, flesh and ashes of a vampire. The more vampires they eat (and the more powerful the vampires are) the stronger the human becomes. A human who devours a vampire becomes an Eater, and thus can act as vampirekind's predators.
Some ordinary humans (non-Eaters) are incredible enough that they can hold their own against the supernatural. Human Traugott Giessendörfer was the runner-up in a fighting tournament of supernatural beings, losing to a scylla called Melina. The human Lorenz is implied to be strong in his own right, and easily counters a young teenaged dhampyr by the name of Watt Stalf (although it should be noted that most dhampyrs typically never manifest traditional vampiric abilities).
Further still, there are some ordinary humans who work as vampire hunters and exterminators without ever becoming Eaters (the concept of an Eater often repulses them), such as the humans who work for Otherworld Welfare Inc. Branch 666. In the specific case of Otherworld Welfare Inc, its members prey upon the weakest of vampirekind, like those who cannot stand the sunlight and sleep in their coffins all day.
There are also some vampire hunters who are loners, rogues acting on their own personal desires (such as the Hunter who attempted to murder the vampire Rude Gardastance).
The supernatural world has conflicting opinions when it comes to humans. The majority of vampires in Clans look down on humans as inferior creatures, and view them as prey and slaves. Members of The Organization have a more neutral and sometimes even favorable view of humans, though of course there are many members (lke Dorothy Nifas) who do not like humans at all.
The human residents of the island Growerth have had a long history of voluntary coexistence with supernatural beings. However, the island's modern youth no longer believe in creatures like vampires, and do not put much stalk in their elders' warnings.