You are either born that way, or someone infects you with it. In this day and age, when most people who are in authority don't even acknowledge the existence of vampires and society is still relatively diurnal, being a vampire your entire life is a painful and frightening experience. Unfortunately, for some reason most vampires do not keep their offspring, but instead opt to adopt them out. Often, the congenital vampire will be confused and more than a little afraid for his sanity and health until he makes contact with others of his kind. In many cases, the vampire may end up permanently damaged, or worse yet, institutionalized by his well-meaning adoptive parents.
Congenital vampires tend to show more resilience physically than their infected counterparts.
They seem to be more resistant to disease, exhibit a faster recuperation from illness or injury, age more slowly and show more overall durability than either humans or their infected brethren. Conversely, the congenital vampire seems to suffer more severely from the adverse effects of prolonged sunlight exposure, has a bigger problem with photosensitivity, and has a markedly lower tolerance for the herbivorous dietary spectrum. If the blood of a vampire is ingested or injected, there is a good chance that the recipient will contract the condition. This is not always effective, however, as the immune system of the recipient may actually destroy whatever it is in the blood that carries the infection. Within 24 hours of becoming infected, the potential vampire will begin to suffer almost flu-like symptoms that will last for approximately a week.