LOS ANGELES (AP):

Vampires have been an eternal force in Hollywood horror since silent-movie days, yet they have risen to new heights as the Twilight franchise, as HBO's True Blood and other incarnations put the bite on viewers.

In studio flicks, independent and foreign-language films and small-screen series, there are more bloodsuckers out there today than you can shake a wooden stake at.

With so many vampires afoot, will Hollywood's favourite night creatures lose their flavour with fans?

"Will there be a vampire glut? Will the vampire market crash? I don't know," said Chris Weitz, director of November's The Twilight Saga: New Moon, part two in the movie series based on Stephenie Meyer's vampire-romance novels. "It's kind of the only growth industry in America, that I can tell."

So many of Dracula's brethren are being sired nowadays that Weitz and his brother have duelling vampire films out this fall.

Paul Weitz's Cirque du Freak: The Vampire's Assistant opened last Friday, with John C. Reilly as a centuries-old bloodsucker in a traveling freak show.

While vampires have a strong pulse in Hollywood, some expect the genre could bleed out from overexposure.

"Sometimes there are trends with audiences and with film studios, TV stations, and they go wild, and they run like lemmings in one direction until they go over the cliff," said Werner Herzog, who directed 1979's Nosferatu the Vampyre. "The genre of vampire films in its darkness and in its nightmarish aspect is a genre that will be forever, but sometimes, you have an overload, an overkill, and when the heap gets too, too big, everybody starts to turn away."

In his 2007 Antarctica documentary, Encounters at the End of the World, Herzog wisecracked that he was not making yet another movie about penguins, a reference to a spate of films on the cold-weather birds.

Penguins reached a glut after only a handful of movies, but the sheer variety of vampire stories lends them superhuman durability for exploring the issues and fears of mortals.

"I think vampires are richer veins than penguins," Reilly said. "There's only so much you can do with penguins. They're cute. They can't fly. They live in snow and ice."

Vampires benefit from modern fans' hunger for fantastic stories. Otherworldly tales once were aimed mostly at specialised horror, science-fiction or fantasy audiences, with a Star Wars or an E.T. the Extra-Terrestrial occasionally breaking out to huge crowds.

Movie-goers today besiege theatres for out-of-this-world stories, from Harry Potter and The Lord of the Rings to the latest adventures of Batman or the X-Men.

"We're at a supernatural height right now with superheroes and science fiction. I think it's all being embraced, with Battlestar Galactica being a critical hit and Iron Man being a huge mainstream hit," said Meredith Woerner, whose book, Vampire Taxonomy: Identifying and Interacting With the Modern-day Bloodsucker, hits stores in early November. "It's a great time where people are ready for some magic."

Vampires have been hardy souls on screen for ages, dating back to the 1920s and '30s classics such as Nosferatu, Vampyr and the original Dracula, with Bela Lugosi. Dracula has been played by countless actors, among them Lon Chaney Jr., Christopher Lee, Frank Langella and Gary Oldman.

Movies and shows such as The Lost Boys and Buffy the Vampire Slayer transfused teen power to vampire tales, helping to open the current vein of hip, pretty young dead things in the genre.

"What's particular about them now is it's coinciding with the optimum market for TV and film. It's that young market; it's kind of the Dawson's Creek thing," said Michael Sheen, who co-stars as the vampire Aro in the Twilight sequel and played a werewolf in the Underworld vampire franchise. "Whereas in the past, I don't think that has been the case. The symbol of vampires has never quite hit that marketing gold."

Along with True Blood, recent TV bloodsucker sagas include The Vampire Diaries, Blood Ties, Moonlight and Britain's Young Dracula and Being Human.

Among recent and upcoming big-screen stories are Blood: The Last Vampire, the horror comedy Transylmania, Ethan Hawke's vampire Armageddon thriller Daybreakers and foreign-language vamp tales such as Sweden's Let the Right One In and South Korea's Thirst.

Twilight leads the way, its love story between an immortal vampire stud (Robert Pattinson) and a sensitive school girl (Kristen Stewart) proving irresistible to teen and older audiences alike.

So far, fans seem willing to devour as many vampire stories as Hollywood can dish out.

"The truth is, you can't have too many vampire movies, just like you can't have too many zombie movies. Each movie is capable of being allegories for different things," said Cirque du Freak star Reilly. "Ours is this whole other universe for vampires that has nothing to do with Dracula or good-looking teenagers making out. It's this crazy underworld that exists, more like Harry Potter than Twilight, because the regular human world doesn't even know they're there."

While their popularity may ebb and flow, vampires always will have a place in the audience's heart, said Nicolas Cage, who starred in 1989's Vampire's Kiss and was a producer on 2000's Shadow of the Vampire.

"The vampire is always going to be fascinating," Cage said. "It's like the vigilante cop, or it's like the cowboy or the Western. It's part of the fabric of society."