Looking at the mythology of the vampire, their symbolism seems rather obvious, however there are multiple interpretations that may reflect different situations.
As creatures who suck the life force of others to live, a dream vampire may symbolize a situation, person, or relationship that is draining you of energy. A dream vampire may particularly represent a draining intimate relationship due to today’s common association of the vampire with sex.
A vampire might also represent ‘sticking your neck out’ for someone or something that might not be worthy of such action or that might end up costing you much more than anticipated. Vampires can symbolise an actual infection. Your body realises you have become infected and will soon succomb.
On the other hand, the vampire is also a creature of seduction that does not physically age. For those who view vampires in a positive light, the vampire may simply be a charismatic, immortal creature possessing great power. A dream vampire may, to them, represent power or a longing for power. Or, it may symbolize a desire to have more influence over not only their own lives, but over the lives of others and other situations.
For those who admire vampires, their appearance is dreams may also represent a desire for immortality. As immortal creatures, one might view vampires as wise beings who possess centuries of knowledge. The dream vampire may therefore symbolize a thirst for knowledge or it may have some piece of wisdom to impart.