Well, here's the rest of the answer:
6. Even if a vampire feeds once a week, and his victim also becomes a vampire, that is exponential growth, with four iterations a month. First iteration: One makes one, total two. Second iteration: Two make two, total four. Third iteration: Four make four, total eight. Fourth iteration: Eight make eight, total sixteen. 16 vampires at the end of one month, 256 at the end of the second month, 4096 by the end of the third month, 65,536 by the end of the fourth month, 1,048,476 at the end of the fifth, and 33,572,832 vampires at the end of half a year! By way of comparison, there are currently approximately 33 million people who have HIV/AIDS and the disease is a world-wide epidemic. I see people every day in the hospital with AIDS, but never has there been one documented case of a vampire attack. Do the math - vampires are a mathematical impossibility.
As for the idea that vampires existed "a long time ago" consider the estimated global population 5,000 years ago - using the above mathematical rationale, a single vampire converted every human on the globe in less than two years. This falls therefore, under the logic of Occam's Razor - which states that when you have removed every impossible answer, whatever remains, no matter how improbable, must be the truth. Since there is no "vampiric plague" swarming the earth, the logical deduction is that they don't exist.
7. Point of clarification about "vampire" bats: vampire is simply the name we have given them because they do drink blood, same as a flea, mosquito, leech, or spider. Are these creatures vampires? No. They are living creatures, not legendary monsters. They can subsist on blood because of their smaller size and proportionately larger stomach volume. Drinking blood does not make you a vampire anymore than eating raw meat makes you a werewolf, although it might make you a mosquito.
8.The humans who profess to be vampires are victims of an all-encompassing self induced delusion. They are as human as you or I, regardless of their claims, and if they ingest HIV tainted blood they can most certainly contract the disease, esp. if they have any cuts, sores, or lesions in and or around their mouth. It is a very dangerous delusion to be laboring under. Note that there is absolutely no scientific or medical proof that these people derive any benefit at all from the ingestion of blood, and even worse are the so-called "psychic" vampires, because their delusion is one that they cannot substantiate with any concrete evidence at all.
9. There is no "vampire" gene. People are not "born" as vampires. When a woman goes to the hospital for prenatal care there are many tests done on mother and child, even while still in the womb, to check for many things, including genetic anomalies that result in deformities and birth defects. If such a gene existed, in today's world with today's technology it would have been found - we have already completely sequenced the human genome. It would also have to follow Mendel's law of dominant/recessive gene theory. Again, the odds on that many "vampires" all escaping the notice of the medical/scientific community are so low as to be almost nonexistent. The idea that there is a global "vampire community" engaging in controlled breeding to keep the "bloodline pure" is delusional in the extreme.
10. There is no "vampire virus" - as I have already pointed out, HIV is a virus, and look at how fast it has spread - virtually everyone knows someone with the affliction. According to the "vampire websites" there are "thousands" of vampires running around. If that was so then at least one of them has ended up in a hospital for bloodwork when they became pregnant, had a bloodborne infection, was injured in a car wreck, etc, etc, ad nauseum. The anomaly would have been detected and medical science would have isolated it, studied it, applied for research grants on it, published papers on it, and turned it into the talk of the medical and scientific community, as well as making its "discoverers" celebrities and rich beyond their dreams. A virus cannot alter your DNA in such a radical fashion without killing you.
THERE IS NO VAMPIRE VIRUS. V5 is not a vampire virus, it is a form of the human immunodeficiency virus, or HIV - something none of you want. The only site I can find linking V5 to vampirism tells a good story, and the author knows a good bit about viral replication, but the site has no hard scientific proof, or links to other, more reputable sites to back it up. These websites offering V5 as "proof" are offering theory only, and have no actual proof that "V5" actually exists! One site claims that the knowledge is being "suppressed" - but if that were so, how'd they find out? And why is the website still up? Because it's fiction. Further investigation of "V5" produces only one further lead: to actual medical reports on HIV.
I'm a Nurse, real education, real experience. No matter what people tell you, "vampires" cannot drain you psychically, cannot gain supernatural nourishment from blood, and are not in any way shape or form "energy deficient". Humans do not give off prana, chi, the Force, or anything else that so-called "psy vamps" say they feed on. These are lies of the "vampire community" with absolutely no evidence to back them up, and are used in order to give their fantasies pseudo-legitimacy to people who are gullible enough to swallow this tripe hook, line, and sinker.