The Cruor Adficio Poxviridae Macrovirus

The Cruor Adficio Poxviridae Macrovirus
An exert from the work of Dr. Calvin T. Mendel, the first scientist to study the vampire phenomenon.
The so-called vampire is really a fascinating creation of evolution. The microscopic virus, which causes the disease directly, can be classified as a retrovirus. A retrovirus uses RNA as its base template, which is transformed into DNA and integrated into the hosts genetic structure. Upon initial observation, the virus may seem rather impotent, as it can only reproduce itself in the skin and blood cells of the host. Even then, its rate of reproduction is slow, but it is in this slow rate of reproduction that the virus's true potential lies. Because it targets fast-growing parts of the body, it does not severely impact the hosts ability to survive. However, the deterioration of the skin renders the hosts vulnerable to ultraviolet radiation.
Now, this phenomena is nothing new, feline HIV and the common cold are two examples of how a virus can reach an equilibrium with its host, but what is truly unique about this virus is its affect on the cellular genome. While the virus cannot reproduce in cells other than the blood and skin cells, it does penetrate other cells and affects their genome. Specifically, the virus genome increases the production of testosterone, HGH, and other bodily growth hormones. This results in a significant boost in the hosts physical ability and aggressiveness despite the loss of blood suffered. In addition, many hosts are able to recover from injuries faster than usual.
The intriguing stage of the virus's infection is its affect on the brain. Inside the brain cells, the virus's infection causes a slight increase in serotonin, which correlates to an increase in aggressiveness in general, but in patients suffering from the virus, it seems to create a specific craving for blood. Whether or not this is a reaction of the brain due to the virus's direct intervention or the brain's reaction to a lack of blood in the system is unknown. Regardless, patients of the virus are more prone to violent behavior, and are very keen about drawing blood. Once they have, many are confused about how to proceed, and some, if left alone for long enough, will attempt to consume the blood.
The combination of all theses effects leads to the transformation of the host into what I have dubbed a marcrovirus. Because the virus attacks the skin cells, it makes the host much more likely to bleed, releasing the virus from inside the host's blood stream into the outside world. The increased aggressiveness of the host makes the loss of blood much more likely, raising the probability that the virus can be transmitted. In addition, the virus has been shown to be present in trace amounts in the reproductive fluids, but has not been proved to actually cause transmission. In this way, the host functions to spread the infection as much as the actual virus does.
While this virus does function like any other, it is very difficult to inoculate against because an ordinarily, exposure to the virus is associated with intense injury and stress, both of which render the body unable to defend against the virus regardless of previous exposure. It has been observed that a few individuals have apparent immunity from the disease. Research is currently being done to isolate the factors that control the bodys reaction to this disease. I have discouraged the final and most controversial approach to controlling vampires for ethical reasons, but I feel that I must mention that ultraviolet radiation is harmful to the host's body (as I mentioned previously) and can be used in order to control the diseases spread. Traditional methods of repelling vampires seem fairly useless, but they do seem particularly vulnerable to other blood-born diseases, having a low red-blood cell count to begin with.
Lastly, I would like to address the claim that the contraction of this virus leads to immortality on the behalf of the host. Up till this point in time, there is no indication that patients suffering from this disease have any alteration in the aging process, but I do concede that the virus's effect on the hosts genome is significant. If there is indeed a gene that regulates our mortality (which has not been proven by any measurement), then it is possible that vampirism could affect this gene.

From A History of Vampires by Charles Graff
The origin of vampires seems to have spawned from a group of settlers who attempted to create a colony in South America on Earth in 2100. The settlers contracted a blood virus, and should have died by all accounts, but miraculously survived, carving out a respectable life in the wilderness when many other cities were experiencing overcrowding. However, when they came to visit family or friends, their associates reported them as changed or different. When asked to describe the personality alterations, they described many of the symptoms that are associated with vampirism today, increased aggressiveness, an obsession with blood, and a sense of detachment from everyday concerns. This is the more accepted theory of vampiric origin in the scientific community, but many believe it fails to account for the intricacy of the virus's effect on the body and particularly the mind. The proponents of this theory held that this level of sophistication in a virus would take millennia to evolve, making it possible that vampirism has been with us for the better part of human existence. This theory is also supported by the fact that the first person to display clinically vampire traits was Vlad the Impaler, who died long before 2100.
Regardless of its origin, vampirism spread rapidly among city populations for the next ten years before being officially studied and classified by Dr. Calvin T. Mendel. Inoculations to the virus were met with mediocre success, and by 2120; vampires were on the verge of being declared a new species. Unfortunately for vampires, contained fusion was also discovered in 2120. Contained fusion allowed for the production of massive quantities of UV light, which proved devastating against vampires when weaponized. As contained fusion became available to the public, anti-vampire vigilante groups began to spring up, using homemade weapons against the vampire populations.
Perhaps a truce could have been reached if both sides had tried harder, but by the time the vampires had mobilized into an effective counter-force, neither side was keen on negotiating. The following war was devastating for the vampires, with casualties ranging from 70 to 80% of their original population. In addition to contained fusion guns, blood viruses created by genetic engineers proved highly effective against civillian targets. In response, the remaining vampires fled to planets not dominated by humans, or merely chose to stay in transportation jobs, away from human-controlled worlds.

"Killin' Vampires" A speech by General Arthur Bascando
Look at you bunch of filthy, rag-tag, lazy, slipshod, halfsteppers! How the hell are you ever gonna defeat a single one of those damn Fangers!!? You think because you have a piece of the sun in your hand, you'll somehow become fucking Van Helsing?! Don't think for a minute that you won't be quaking in your boots when you see those Fangers in their combat gear, black suits and high-powered rifles, cause you will!! I wont be surprised if I see some of you shit your pants, you load of miserable cowards! They're tricky bastards, Ill give you that. They're clever, too, they'll slip behind you with a smile and bite your fucking neck if you give them the chance!
Don't forget that for one second! They ain't human, and they ain't ever gonna be, so they might as well be dead before they take you with 'em! Now, you listen here, and you listen good. We got these bastards in a corner now, see? The only way they can get off the planet is back the way we came. Our pilots spent all last week gassing their pale asses, so I want everyone to have their mask on firm and tight k? We got 'em now, all you gotta do is point your gun and blow their goddamm heads off! Then you can go back to your friends and your bitch and brag about how you shot a Fanger, and how they're safer because of you and blah blah blah. Well first, you got to shoot a Fanger, now dont'cha?
I want you to hold up your gun right now! This is the dee-vine weapon granted to you to smite these unholy fuckers from under the sun that they fail to embrace! I want to hear you scream with pleasure each time you pump the holy light power into their sorry asses! You're gonna rip them a new one, and turn them all into fucking dust! Oh, and don't touch any of the women, k? You can catch it that way, too.