While in theory HVV infection is possible through any exchange of bodily fluids, transmission occurs through the bite of an infected person in virtually every case. Although the tiny dose of virus present in the saliva that passes during a feeding is usually insufficient to infect a healthy human, if enough blood is withdrawn to sufficiently deplete a victim's white blood cell level, the immune system will be overcome and they will be infected with HVV. If the victim's blood loss is not severe enough to discernibly compromise the immune response, the virus is easily dealt with by the immune system and eradicated.

Stages of infection

Within hours of being bitten, the victim develops a headache, fever, chills and other flu-like symptoms as the body tries to fight off the infection. These symptoms can be easily confused with more common viral infections, although the presence of bite marks on the body are usually enough to confirm the diagnosis. This stage generally lasts between six and twelve hours.

Within 24 hours of being bitten, the victim will slip into a Vampiric coma. During this phase, the pulse slows, breathing is shallow and the pupils are dilated. The large numbers of people mistakenly buried alive while in Vampiric comas gave rise to the myth that Vampires sleep in coffins. While it is commonly thought that anyone infected with HVV turns into a vampire, in fact only a small percentage of people survive Vampiric comas. Generally, the young, the old and the feeble never come out of their Vampiric comas and eventually die. The vast majority of people who survive Vampiric comas are males between the ages of 18 to 35. Vampiric comas last about a day; the victim usually comes out of the coma the night after its onset.

A bite victim who survives the coma will awaken fully transformed into a Vampire. An acclimation period follows, characterized by confusion, despondency and paranoia. Most Vampires begin to hunt within 24 hours of transformation. The vaccine is of no use at this point.