Amelie: Have you children any concept of geometric progression?
[Claire raises her hand]
Amelie: And how many vampires would it take to turn the entire world into vampires, if it was so simple as that?" [Amelie smiled as Claire opened her mouth.] My dear, I do not expect you to answer, though if you would like to work out the math of it and tell me someday, I should be most interested to see it. The truth is that we came very near to it, in my younger years, when humans were much fewer. And it was agreed — as it has lately been agreed among you humans — that perhaps conservation of game is a wise idea. So we — removed the knowledge of how to create more vampires, simply by refusing to teach it.
Vampire-bite victims becoming vampires themselves is a staple of vampire fiction. However, if every bite victim turned, this combined feeding-and-procreation method would logically lead to vampires rapidly outnumbering their human victims. While many works leave vampire population logistics unexplained, others choose to address the population implications head-on, either by incorporating a Vampire Procreation Limit that prevents a vampire population explosion or using it as a variant on a Zombie Apocalypse plot.
A particularly common method, popularized by Anne Rice, is to require the new vampire to receive a transfusion of blood from an existing vampire in addition to being drained. But there are other possibilities such as requiring the potential vampire to have a specific gene or even making vampires a separate species that reproduce sexually.
A subtrope of Our Vampires Are Different. Compare Immortal Procreation Clause or Dhampyr.
- In Blood+ Chevaliers are produced by feeding a Chiropteran Queen's blood to a human dying of blood loss. The common, "feral" Chiropterans are artificial, produced via a drug isolated from Queen's blood. The Queens themselves though, reproduce sexually, they are born in pairs and eventually one Queen's Chevalier mates with her sister.
- In Hellsing victims of vampiric feeding do rise as the undead, but only virgins become vampires, everyone else becomes a flesh-eating ghoul. Which is why the vampire priest in the first chapter attempts to rape Seras Victoria before eating her, and Alucard asks if she's a virgin before shooting through her. Then a later vampire attack features some victims becoming ghouls despite being far too young to not be virgins, suggesting that something unusual is going on...
- Vampires in Karin reproduce sexually, but a good majority of them are infertile and have trouble conceiving. There are certain vampires known as "psyches" who are capable of bestowing fertility by sharing their own blood. Karin just happens to be one herself. Her family never really catches on that this "un-vampire" who is capable of living out in sunlight, eat normal foods, and creates blood instead of consumes is actually The Chosen One who can restore fertility among vampires by sharing her own blood.
- In Negima! Magister Negi Magi, Evangeline's vampire bites simply drain blood or allow her to control those she bites. She states that she can create other vampires, but this never occurs in the story. This is likely because she was born a regular human and simply the victim of an immortality experiment by The Lifemaker, and thus isn't the genuine article. The sequel UQ Holder! would introduce actual vampires who prefer to exist in their own society and not bother with humanity.
- In Shiki, some humans become vampires after being sucked out while others do not. The exact causes are not known, but it is speculated that it may have genetic causes. For a human can not become a vampire if at least one of his parents can not become one. The real luck, however, is to become a jinrou, but only very few humans can do that.
- In Vampire Knight most vampires reproduce sexually with either other vampires or humans (the Purebloods are vampires who have almost no human ancestry and are the most powerful). Rarely, some humans who are bitten by vampires and survive (most die of poisoning or blood loss) turn into Level D vampires; unless they drink blood regularly or drink the blood of their creator they eventually descend into Level E vampires, who are savage and insane monsters with no trace of humanity left.
- Big Finish Doctor Who: In "Litefoot and Sanders", it is revealed that someone killed by a vampire will not as a vampire themselves if the vampire drains all of the blood from their body. As a result, most vampires are careful to do this. However, if a vampire does leave some blood behind in the body, then the victim will become a vampire.
- It isn't explicitly stated, but the circumstances of Cassidy's vampirisation combined with the events of the Blood and Roses miniseries suggest that you become a vampire in Preacher by being bitten by a vampire and surviving, in a disease model. Vampires are rare because they generally go into a feeding frenzy when they bite people, and only fail to drain them to death if something interrupts them. They also don't have fangs, so Vampire Bites Suck because they generally tear your throat open to feed. The line between "bite that changes you" and "death" is very narrow.
- In 30 Days of Night, every human who is bitten (or even scratched) by a vampire will be turned into one, too. Even if they are not killed. Because of this, the vampires almost always behead or burn their victims to avoid creating new vampires. But they do not seem to be very careful, because over the course of the movie at least four humans turn into vampires.
- In Blood Red Sky, Nadja tries to enforce this when, after biting Berg, she stabs him in the heart as he starts to turn, and when she tries to set Eightball on fire. Unfortunately, the plane's fire suppressant systems kick in before Eightball dies, and he infects the rest of the hijackers save for Bastian, who was safe in the cockpit flying the plane. By the end of the film, everybody aboard the plane save for Elias and Farid is a vampire, and Elias has to blow up the plane to stop them from overrunning the airbase after they pounce on the search-and-rescue team and start pouring out of the plane.
- In Byzantium, vampires are created by travelling to a remote island - the location of which is known only to other vampires - and being turned by some kind of Eldritch Abomination that dwells there. It's further stated that only those who are ready to die - primarily the terminally ill - can become vampires. The Brethren - the de facto leaders of the vampires - also have rules in place about who can and can't become a vampire; they usually only approach men of high social standing for recruitment and women are forbidden from facilitating the creation of vampires, with the punishment being death to both the creator and her progeny.
- Daybreakers: The aversion of this trope is the entire basis of the plot. When vampirism first emerged, the vampires bred explosively, and ten years later the vampires outnumber the humans easily twenty to one... and are starving to death as a result, since they can't feed off each other without going insane.
- Fright Night (1985): Jerry just decapitates his victims, since having other vampires running around would give him away. He turns two (Amanda, Ed) because he's using them against Charlie and Peter.
- In The Lost Boys, a person becomes a half-vampire by drinking a vampire's blood, but won't become a full vampire until they drink human blood (which is increasingly difficult to resist).
- Love at First Bite is more concerned with being a comedy spoof than nitpicking vampire lore, but it still establishes that a would-be vampire has to be bitten three times before they turn.
- Stake Land deliberately averts this trope, and goes the "vampirism as Zombie Apocalypse" route of I Am Legend, with civilization collapsing as vampires take over.
- In Underworld (2003), vampirism is transferred virally via a bite, though Selene states that most humans who get bitten just die instead because their bodies can't handle the mutation; anyone who wants to become a vampire is taking a gamble. Vampires can conceive 'pure-born' vampires, but it's implied this is quite rare.
- In The Coldest Girl in Coldtown, vampirism is a virus which spreads through biting. Infected people are referred to as having "gone cold". It can take up to sixty-eight days to heal from the time of being bitten, but a person will only become a vampire if during these sixty-eight days, the person consumes human blood before the infection is out of their system. Originally, vampires kept their population down by killing everyone they fed on and enforcing harsh restrictions on the creation of new vampires, until one compassionate but stupid vampire, the infamous Caspar Morales, started a vampire pandemic by letting everyone he bit live. In modern nights, vampires avoid spreading the infection every time they want a snack by using razors or stents. (The real jerks may bite someone directly and then keep the unfortunate bite-ee chained up and muzzled.)
- In the Discworld novel Carpe Jugulum, Vlad explains to Agnes that people bitten by a vampire only turn if the vampire chooses, which is rarely the case. Vampires can also reproduce normally, he and his sister were born vampires.
Vlad: When you eat ... now what is it you eat? Oh yes, chocolate ... you don’t want to turn it into another Agnes Nitt, do you? Less chocolate to go around.
- A Dowry of Blood: Vampires are only able to sire new vampires if two methods are used. The vampire in question must be over a thousand years old as it's only than that their blood is mature enough to sire new vampires, and they and the one they're siring into a vampire must exchange blood.
- Bram Stoker's Dracula is ambiguous as to whether it works this way. The Count forces Mina to drink his blood, forming a mental link between them, but he's not shown doing this to any of the other women he turned. On the other hand none of the ship's crew he ate rose as vampires.
- The Dresden Files has a Vampire Variety Pack:
- The Black Court are the classical Draculas, except they appear to be corpses in varying stages of decay. (Dracula was a treatise on the Court's strengths, weaknesses, and how to hunt them disguised as a novel, commissioned from Bram Stoker by their rivals in the White Court.) The Black Court is acknowledged to be the most explosive breeders, their victims getting right back up immediately, but their numbers are thinned by vampire hunters and other rivals, making them the most rare.
- The now extinct Red Court were basically humanoid bat monsters, capable of developing a second skin to disguise themselves as human. An unknown process (other than that it's not just biting itself as that only leads to blood loss and a narcotic drugging effect)can convert a human into a half-vampire with a human appearance, the benefits of which include agelessness and strength, but would incur a strong blood thirst. When a half-vampire kills another person for their blood, they then transform into a full Red Court vampire. The Red Court was known to be the most populous Court, considering the relative ease with which they breed and their fairly low profile.
- White Court vampires are people with a demonic symbiote called a Hunger that turns them into vampires that can invoke and feed on emotions, the head family preferring a diet of lust (fear, despair and anger being diets of choice for some others). They can only reproduce sexually, producing human offspring with an embryonic Hunger attached. When the child of a White Court vampire loses their virginity, the Hunger awakens and kills their partner by draining them and turning the child into a full vampire. Both sexes appear to be somewhat fertile, with Lord Raith having had many children over centuries and Justine referring Lady Malvora as a mother of another vampire. But, they are also explicitly very low in fertility. Even if they do concieve pregnancy is also very dangerous for at least human mothers with a 50% survival rate to full-term. This all means that there is often a couple decades between even incubus Lord Raith being able to successfully have a child born.
- There are other vampire courts, the biggest being the secretive Jade Court in East Asia, but they're too small or secretive for concrete information on them.
- In Evernight, only people who have been bitten multiple times before by a vampire can themselves become vampires, and even then this is only true if the last bite is fatal. Vampires can produce children sexually but this is an extremely rare occurrence, only happening about three or four times a century; it's further revealed in Stargazer that it's impossible for vampires to conceive unless they partake in a ritual with wraiths, and wraiths and vampires don't get along much.
- I Am Legend by Richard Matheson is the canonical exploration of what happens when this trope is deliberately averted. In short, despite being a vampire novel, it is considered one of the progenitors of the Zombie Apocalypse story, one that George A. Romero even cited as inspiration for Night of the Living Dead (1968).
- The Laundry Files (by Charles Stross): In The Rhesus Chart, it's explained that because the existence of only a few vampires would be enough to dramatically increase the murder rate in Britain, vampires maintain The Masquerade by the simple method of killing off any other vampire they encounter. In this case vampires are created by magical means, but anyone fed on by a vampire dies no matter how little blood is drained.
- In Lost Souls (1992), vampires are a separate species who cannot turn humans into their own kind; you must be a born a vampire. Vampires can interbreed with humans, although it's implied that it's not guaranteed that the resultant offspring will be a vampire. Another complication is that vampire pregnancies are pretty much always fatal to the women carrying them, even if the woman is also a vampire, due to the fetuses devouring their mothers from the inside. As such, there aren't very many vampires because procreating is so unpleasant; one of the few female vampires mentioned in the novel tried to avoid ever having sexual intercourse out of fear of pregnancy, but got pregnant anyway after being raped.
- In Morganville Vampires, during the early years of vampires, vampire numbers almost overwhelmed the human population due to their ability to transform humans into vampires rapidly as well as the human population being smaller than it was today. In order to prevent the humans running out and hence endangering the vampire's food supply, it was agreed by the higher vampires of the time to remove the knowledge of how to create more vampires, simply by refusing to teach it. Over time, this knowledge became lost even to the elder vampires resulting in it only being available from two sources, these being the world's oldest vampire, Amelie as well as an ancient spell book where it was written down.
- The Mortal Instruments has a very complex ritual to turn a human into a vampire. At first, they must not suck him completely, and then he has to drink the blood of a vampire. Shortly thereafter, this human must be buried in holy ground. And even then, not every newly-transformed vampire is strong enough to free himself from his grave.
- In My Vampire Older Sister and Zombie Little Sister, a vampire can only transform a human into another vampire by sucking a lethal amount of blood. Additionally, they form organisations to track the humans that they feed on in order to control the creation of new vampires.
- In the Night Watch (Series), vampires are Dark Others whose creation is regulated by the Treaty. As such, each vampire must receive explicit permission from the Night Watch to turn a human, otherwise the Night Watch has a free reign under the Treaty to hunt down and to destroy both the progenitor and the progeny.
- Night World: Vampires can only create other vampires by repeatedly exchanging blood with a human (or witch) - they drink the human's blood, then let them drink some of their own. If they don't get the balance exactly right, then the human can just die, or turn into a ghoul. It's further established that most people older than their teens cannot physically handle the transformation and their bodies will just "burn out". The Elder Council have also placed a ban on making just any human into a vampire, partly because turning someone requires you to break cardinal law no. 1: Never tell a human about the Night World. This actually drives some of the conflict in Secret Vampire, as James turned Poppy illegally, knowing he'd never get permission because he broke cardinal law no. 2: Never fall in love with a human. Lamia vampires can procreate the old-fashioned way, but made vampires are infertile.
- Vampires in The Parasol Protectorate have their spread limited by a number of factors. Like their werewolf counterparts, they can only turn certain individuals with “excess soul,” which can’t be reliably predicted. In addition, they have a psychic tether to their homes that will drive them insane if they stray too far from the hive, and only the rarer female vampires are capable of inducing the change.
- In The Saga of Darren Shan a vampire cuts the tips of his fingers and his new "assistant's" fingers and presses their cuts together so that their blood mingles. Notably the process has to be done at least twice, the first time only converts them into a Dhampyr.
- The book series The Saga of the Noble Dead shows that some humans are sucked out, then become vampires, and other humans are not. But that depends on chance.
- In The Sanguine Chronicles vampirism and lycanthropy are caused by two strains of a virus that most people are immune to. If you're not immune and are attacked by a vampire or werewolf you tend to get infected. Marko is the result of his mother getting caught in the middle of a Fur Against Fang fight while pregnant with him.
- This is the policy of the Vampire Nation in Straight Outta Fangton by C.T. Phipps. In order to create a new vampire, you have to have permission of the voivode of the area. This is a recent rule, though, because so many humans were turned in the wake of the Reveal. Many of the newly created humans do not adapt well and eventually go feral or commit suicide. This is obviously bad news for their publicity.
- In Team Human the vampire population is kept down by three factors: The vampire has to completely drain a human to make a new vampire. It is against both human and vampire law for a vampire to turn a human into a vampire without that human's permission (and most vampires are law-abiding). Sometimes the attempt to turn a human fails, and a mindless zombie is produced instead.
- In Trinity Blood only people carrying a certain gene are susceptible to the Martian bacterium that turns humans into vampires (or Methuselahs as they prefer to be called). Most Methuselahs are born to vampire parents. And only Artificial Humans like the Nightroads can survive the Crusnik Nano Machines.
- In The Twilight Saga, any living victim with vampire venom in their system will transform, but most people-eating vampires don't have the willpower to stop before the victim is dead, and the venom will just kill animals no matter what. Breaking Dawn reveals that male vampires can impregnate female humans with hybrid offspring, but the bodies of human women are too fragile to handle the pregnancy, as the fetuses are preternaturally strong and need blood to survive, which takes a big toll on the woman's health. Most hybrids inadvertently kill their mothers before they can give birth, often resulting in the death of the child too. Even conception is risky, as many male vampires lack the self-control to impregnate a human woman without draining her blood or otherwise damaging her body.
- The Vampire Chronicles by Anne Rice popularized this version. In Interview With the Vampire the process is described as the human and vampire sucking each other's blood.
- In The Vampire Diaries, a human who consumes vampire blood and dies within 24 hours can revive as a vampire.
- Buffy the Vampire Slayer:
- It establishes this in the first episode when Buffy explains to Giles why the first victim we see won't return as a vampire.
Buffy: To make you a vampire, they have to suck your blood. And then you have to suck their blood. It's like a whole, big, sucking thing. Mostly, they're just gonna kill you.
- In addition, vampires are normally possessed by demons upon siring. After Buffy destroys the Seed of Wonder that allowed demons to enter the world, attempts to sire vampires produce mindless "zompires".
- It establishes this in the first episode when Buffy explains to Giles why the first victim we see won't return as a vampire.
- In A Discovery of Witches, vampires can turn dying humans into vampires via a blood exchange; however, it doesn't work on humans that are already dead and they also have do transformations in a way that doesn't threaten The Masquerade (Marcus gets chastised for trying to turn his surgeon friend after he's fatally struck by a car in broad daylight, even though Marcus argued there was no one about and he couldn't just let him die). Another huge complication is that in the past fifty or so years, most vampires’ attempt to make more of their kind has failed, with the humans just dying instead even if the exchange is completed in time; this is linked with the decline of magic in the world. Matthew de Clermont and his ‘siblings’ have been researching a way to resolve this problem.
- My Babysitter's a Vampire: Humans bitten by vampires will typically become vampires themselves, however there are two ways of getting around this; a fledgling vampire that does not drink blood will die in 28 days if they can't find a blood substitute to sustain them, while also not having all their abilities. A human who has the venom drained from their blood before transformation will be spared from transforming at all.
- In Preacher, vampires are able to turn normal humans into vampires easily enough, but the vampire population is limited because the race has a terrible epidemic of Chronic Backstabbing Disorder that drives them to attack and kill each other.
- Supernatural. The vampires don't try to increase their numbers because there are billions of humans who would wipe them out if they tried. They prefer to maintain The Masquerade and take their chances with the occasional Hunter.
- True Blood also does the "drain, then feed" technique, with the added limiter that newly created vampires have to spend one night in the grave with their maker for the whole process to take.
- What We Do in the Shadows (2019): Humans bitten and drained by a vampire for food simply die. In order for them to become a vampire, they have to be actively sired by the vampire that bit them. Many familiars to the vampires became a familiar in hopes of one day getting sired by their master (which most never do, despite promising otherwise).
- Contagious vampires are actually rare in the assorted folklore that inspired them. In most cases they spontaneously arose from a corpse that died under certain circumstances, such as suicide.
- Romanian strigoi actually reproduced sexually, mating with humans to produce Dhampyrs who became strigoi when they died.
- Dungeons & Dragons 3rd Edition: A humanoid with four or fewer Character Levels or Hit Dice doesn't become a vampire if drained of blood by one; instead, they rise as a less-powerful "Vampire Spawn" that can't turn people.
- In Ironclaw vampires, or "oupires", aren't contagious, they're produced by necromancy or bargains with dark powers.
- Magic: The Gathering acknowledges in-story that between their decadent feeding habits and competition from many other man-eating horrors, the vampires of Innistrad would have run out of humans to eat long ago and consequently starved to extinction. Seeing this, the planeswalking vampire Sorin introduced a conservation program of sorts in the form of Archangel Avacyn to give humanity a fighting chance. This wasn’t exactly appreciated by his kin, and now that she’s dead it’s anyone’s guess what will happen.
- In the Zendikar setting, only the bloodlords are able to produce new vampires. If their "children" try to, they just end up with mindless zombies called nulls.
- Vampires in Urban Jungle are produced when an occultist allows a malevolent spirit to possess him. Victims of their feeding are essentially zombies that drink blood.
- Vampire: The Masquerade and its successor Vampire: The Requiem:
- Vampires reproduce by exsanguinating a human to the brink of death, then feeding them a few drops of vampire "vitae" and making a huge effort of will to revive them. The games represent this differently: in Masquerade, siring requires the expenditure of a Willpower point, meaning mass creation of vampires is a possible tactic. (Nevertheless, this doesn't usually lead to more vampires in the long run; mass Embraces are used to generate expendable cannon fodder for Zerg Rushes, and the vampires involved neither expect nor want their progeny to survive.) In Requiem, creating a full-fledged vampire requires burning a Willpower dot, which can only be bought back in time; trying to create a vampire by just spending a Willpower point will create a feral half-vampire. Feeding vitae to a healthy human temporarily empowers them as a Ghoul instead.
- Masquerade also ranks vampires by "generation", i.e. how far removed from their antediluvian vampire progenitors they are. Most Player Characters start between 10th and 12th generation; 13th generation vampires only have a 50% chance of being able to sire useful offspring, who are usually "thin-blooded" with weakened (though often unique) powers. Some thin-bloods, aka the Duskborn, are able to Embrace childer, but it's a lot harder and there's a much higher chance of just ending up with a dead body.
- In Masquerade, there's also an artificial limit in some cases. In the cities of the Camarilla, the Prince, the highest authority, is the only one who can award vampires the right to sire. Anyone who tries making a kid without their blessing will face punishment, possibly destruction; this might also fall on the kid, too.
- In Warhammer, making a new vampire requires secret elixirs based on Neferata's research (and Neferata herself became the first vampire by trying to make an immortality elixir from studying Nagash's scrolls).
- In Baldur's Gate III, Astarion explains that being non-fatally bitten by a vampire turns you into a "vampire spawn"; they have some of the abilities and traits of a full vampire, but are nowhere near as powerful and are under the thrall of their creator. If they were to drink the blood of their creator they would become a full vampire themselves, but as Astarion points out most vampires are competitive and power-hungry, so there's not much motive for them to willingly elevate a thrall into a potential rival.
- Cute Bite explains that turning someone into a vampire requires a deliberate act and also an incredible amount of willpower (the Dominance stat, in-game). A human bitten by a vampire is just low on blood. A human who drinks a vampire's blood gains increased lifespan at the cost of a mind-controlling blood bond, but doesn't become a vampire.
- The Elder Scrolls series treats vampires as being Deceased and Diseased, but being attacked by a vampire does not guarantee being infected, and the disease takes about three days to completely transform the infected into a vampire, giving those who don't want to transform a reasonable amount of time to seek a cure. There's also the Daughters of Coldharbour (first mentioned in the Dawnguard DLC for Skyrim), women who become Vampire Lords by partaking in a ritual with Molag Bal, but considering this is Molag Bal we're talking about...lets just say that very few women actually survive the ritual and when asked about it, Serana only states it was "degrading" and she'd rather not talk about it.
- In Heroes of Might and Magic Ashan, the process of creating a vampire involves gradually replacing a human's blood with venom milked from namtaru spiders. Because many necromancers are deeply religious and consider namtarus sacred creatures of the goddess Asha, vampirism is considered a reward for a lifetime of service to the necromancer's cause, and is almost exclusively offered to very old necromancers.
- Town of Salem has vampires as a potential in-game faction. There can only be a maximum of 4 vampires (out of a starting total of 7-15 players. They are also limited in that they can only turn town members into vampires... biting a Mafia member kills them, and other hostile factions are immune to vampirization.
- In Tsukihime, vampires who suck a human's blood can then inject them with some of their own blood to turn them into the Dead (a zombie, for all intents and purposes). In some cases, however, exceptional victims don't die completely, but instead turn into beastly ghouls. By consuming human flesh for many years, ghouls can eventually regain their human intelligence, completing their transformation into a vampire, — but only a few actually manage to survive that long, putting an additional limit on new vampire population. And in even more extraordinary cases (as seen with Satsuki), it's possible for one to immediately become a full vampire. It's also possible for a human mage to use their magecraft to create vampires without the participation of an existing vampire, but this also usually just creates ghouls.
- Played with in The Order of the Stick, where creating a new vampire usually requires an existing vampire to kill someone by completely draining their blood and leaving them in their grave for 3 days. However, particularly powerful vampires have ways to speed up the process; for example, the staff carried by minister Malack has a spell stored in it that can instantly resurrect his victims as vampires.
- Sluggy Freelance has a Vampire Variety Pack of at least three with different reproductive methods.
- Vorpyr are produced through a three night ritual of slow draining of blood and feeding small amounts of blood from their circle's Vampire Monarch. By the time they're introduced they've been reduced to a single circle which is trying to rebuild their numbers, which is then wiped out by the protagonists save for their friend Sam and one other they staked and forgot to finish off.
- Vrykolakas turn everyone they kill, but the majority of them are weak, turning to dust if staked with a toothpick or their sire is destroyed. When their queen and ultimate progenitor is killed almost the entire species is dusted, save for some stronger individuals who are merely weakened.
- The Strakoi's means of procreation haven't been brought up yet.
- Weirdly averted by this (apparently Twitter-original) Micro Flash Fiction:
"Hello! Do you have a minute to talk about Dracula?"
"No— wait, Dracula?"
"Yes. We have pamphlets."
"Vampires have missionaries?"
"Where else would new vampires come from?"
"I assumed you bit people."
"There are many hurtful stereotypes. May we come in?"
- Taerel Setting: Averted, hence why in the year 3E 3000, a vampire outbreak lead to the fall of civilization - as a large amount of the zu'aan population was turned into vampires.
- School For Vampires: Vampires in this series mostly produce sexually, so like humans they are born as babies and grow up from there. It is possible for vampires to turn humans into vampires, but only if they bite them during a full moon. And the process can be reversed by giving the victim a blood transfusion.