As a storytelling device, vampires can stand in for all sorts of real-world phenomena. These classic creatures of the night are usually played for pure horror or unexpected romance, but are most effective when used to explore the issues faced by teenagers. Growing up and going through all sorts of physical and emotional changes is perfect fodder for modern vampiric fables, so it's not surprising that it's been the basis of some great films.
Source：https://www.cbr.com/my-best-friend-is-a-vampire-horror-tropes/
