Ho-hum. Yet another vampire movie. The blood-sucker population explosion continues. Actually, in a way that’s the premise of “Daybreakers,” and it’s a fairly nifty one. Unfortunately, its potential isn’t realized in this gloomy, ponderous picture.

In 2019, the world has become inhabited mostly by bloodsuckers as a result of a plague that began, as news bites at the beginning tell us, with a single bat a decade earlier. Unfortunately, the declining number of humans, who are hunted down and harvested for blood, means that the food supply is reaching crisis proportions. That’s why the chief supplier of the sanguinary stuff, Bromley Marks Corporation, is engaged in research to develop a blood substitute, with CEO Charles Bromley (Sam Neill) pushing his chief hematologist Edward Dalton (Ethan Hawke) to come up with a breakthrough. The need is pressing because vampires who feed on themselves or other vampires are turning into monstrous bat-man creatures that threaten the new nighttime social order.

Edward, however, is a pro-human oddity among his fellow vampires, and when he aids Audrey Bennett (Claudia Karvan), a still-fangless refugee, to escape a police patrol, she recruits him to assist her pal Lionel “Elvis” Cormac (Willem Dafoe), himself an erstwhile vampire humanized again, and their band of fellow-thinkers, in finding a cure for the vampirism and restoring humanity to full strength. But Edward’s hot-tempered brother Frankie (Michael Dorman), one of the government’s human hunters, is in hot pursuit.

All of this could easily have been played with imagination and a sense of humor, but the Spierig brothers (Michael and Peter), who wrote and directed, ignore any real portrayal of the new vampire society (which could have been interesting) in favor of a simple chase scenario, and opt for a glum, dirge-like approach that’s simply enervating. Taking their fantastic scenario much too seriously as a parable of deadly disease, social conformity and corporate greed (Bromley, of course, is one of those avaricious titans interested not in curing the plague but in boosting profits by insuring “repeat business”—like the auto executives who killed the electric car), they treat the story in a solemn, portentous style abetted by typically somber, gray-toned cinematography from Ben Nott. And Hawke adds to the pervasively dank tenor with a performance that’s inexpressive and—if you’ll pardon the word—lifeless. Karvan, who becomes his love interest, is simply amateurish, a description that also pertains to Dorman.

A vampire movie needn’t be jocular, of course, but it should be interesting, and this one—for all the chases, fights and splurges of blood and gore, simply isn’t; it drags mercilessly. Neill provides a few moments of silken malevolence, but even here a subplot involving Bromley’s daughter Alison (Isabel Lucas), who’s fled his vampire clutches because of his desire to turn her into one of the undead, is a real downer. Even Dafoe, from whom one might have expected a wild-eyed turn as a redneck revel, seems curiously subdued. And Christopher Gordon’s brooding, overemphatic score accentuates the self-important feel of it all.

“Daybreakers” succeeds in a way that the Spierigs certainly didn’t intend—it actually makes bloodsuckers boring. It’s a movie about too many vampires that only proves there are too many movies about vampires.