Born vampire

Born vampires are a subspecies of vampire, who unlike most other vampires, were born as vampires, rather than being a human who was turned into one. They are similar to ordinary vampires, but have a number of biological differences. Born vampires that do not become full vampires turn into wraiths.

Creation
How born vampires are conceived is not made entirely clear; however, it is made explicit that wraiths must be involved, as vampires are incapable of creating a new life by themselves. Vampires are said to represent the 'body', whilst wraiths represent the 'spirit'. Celia and Adrian Olivier, two vampires who successfully conceived a child, stated that they weren't too sure how the wraiths managed it, but that they temporarily took "possession" of them during a ritual of some kind. One possible explanation is that the wraiths somehow temporarily transferred their spirit energy into Adrian and Celia, allowing them to conceive a child. Mrs Bethany mentions in Afterlife that the ritual involves a blood exchange (wraith blood is usually toxic to vampires).

Physiology
Born vampires age like normal humans and require both ordinary food and blood to survive. They have fangs and some vampire abilities, such as enhanced speed, agility and senses, but to a lesser degree than a full vampire. Once they reach puberty and have tasted human blood for the first time, they begin to gain more vampire traits. Prior to drinking Lucas Ross' blood, Bianca Olivier wasn't bothered by holy symbols or crossing running water, but as of the second book, they began to affect her. Born vampires are seemingly 'half-human', in that they have human weaknesses to illness and injury (although they apparently have a better immune system than ordinary humans) - Bianca explictly refers to herself as being "half vampire" on a few occasions. Their body temperature is also slightly cooler than the average human's temperature, though not to the point where a human doctor would be concerned. Born vampires are apparently capable of turning humans into vampires, despite technically being only part vampire. At the same time, Bianca is mentioned as menstruating, indicating that unlike ordinary vampires, born vampires are able to conceive naturally without the need for wraiths to intervene. Balthazar More explicitly describes born vampires as being "alive", unlike full vampires, who are undead. Whilst still a born vampire, Bianca Olivier has seemingly prophetic dreams. It is unclear if all born vampires have this ability, or if this is a phenomena exclusive to Bianca.

Born vampires must apparently take a human life to fully transition into a vampire. Once they reach young adulthood, their bodies slowly start to shut down and will eventually die, whilst the born vampire becomes a 'pure' wraith. Presumably, if successfully feed from and kill a human, they will become a normal vampire. Those that don't cannot live as born vampires indefinitely, and will inevitably become a wraith. The first signs of this happening are loss of appetite, even for blood, fatigue and loss of energy and rapidly cooling body temperature. Born vampires transitioning into wraiths feel cold, nauseous and faint, often passing out. After some time, their physical body will die and they become a wraith. These pure wraiths are exceptionally powerful, being able to grasp the powers of wraiths in a matter of days and having a psychic link and control over other wraiths.They can also easily create a corporeal form for themselves and retain it for as long as they like.

Rarity
Born vampires are quite rare, though not so rare that vampires have never heard of them. Celia and Adrian told their daughter Bianca that only four or five of these vampires are born each century. Mrs Bethany stated that Bianca was only the third born vampire she'd encountered since the year 1812. Black Cross, who are considered experts on vampires, had never heard of born vampires until they learned of Bianca's status as one. The reason for the scarcity of born vampires may be due to the difficulty of successfully completing the ritual, as well as vampires' fear and distrust of wraiths, which make them reluctant to seek them out. This would suggest that there are other born vampires out there, but the only one to appear in the series is Bianca Olivier.