You cannot become a vampire, due to the fact you were born human you cannot alter your dna to become a mythical creature, the whole concept of the vampire comes from middle age Europe when people didn't understand what happens to a deceased person's body after death
Actualy,you a part right.Though from legends and so on.Is it not funny how these so called mithical creature can be found in the history of nearly every religion,culture and even have a native name.
Eg:Im from botswana and here.Dark jinn a called thokolosi and demons,matemone.They a similar to elves but trail back,way back.Even before colonisation and can still be seen and befrieanded today even with thier risks.
How if not real,can they they exist in so many continents and countries?
You cannot mutate into any creature, any human seeking blood as a food source has a medical condition, they are not a vampire.
Yes, almost every country has a variation of the same stories, but death, especially in pre - modern medicine times was widely misunderstood, much like lycanthropy it has been formulated in many different countries from the same or similar medical conditions and occurances, that does not make it a fact.