The IMDb database gives this for a plot summary:
"Sean (Kerr Smith) is driving cross-country to deliver a vintage Mercedes and attend his sister's wedding when he picks up a hitchhiker, Nick (Brendan Fehr), who just happens to be a vampire hunter, tracking down a group of youthful vampires that feed on unwary travelers. As the plot thickens, they run into Megan, (Isabella Miko) who has been left for dead by the vampires. As they use her as a lure for the vampires, Sean becomes attracted to her. Further complications ensue when Sean is infected with the vampire virus. He, Megan and Nick must race against time to kill the vampire leader (Jonathon Schaech) to stop Sean from becoming one of the undead."
I scanned through some of the user comments (of which there are a ton, especially given that I'd never heard of this film) while formulating my own thoughts about this movie, and I have to agree with the general assessment that this film doesn't entirely suck, but it's not especially good either.
The things I liked included the character of Nick, the vampire hunter. He was just kind of a dude, you know? In fact, I found myself pleasantly surprised when this easy-going, beer-drinking oaf ended up being the keeper of the arcane knowledge. I really liked the fact that Nick's vampire hunting skillz weren't in the realm of superheroic at all – no Buffy-esque ninja staking moves. As far as I could tell, he had The knowledge, a gun, and "the cocktail," which wasn't actually for hunting vampires at all, but for keeping their victims from turning.
Vampirism as "sexually transmitted" disease is hardly a brand new idea in vampire fiction, but this was the first time that I'd seen it combated with drugs, specifically pharmaceuticals originally formulated to help HIV patients survive longer. I couldn't decide, however, if this detracted from the film or made it cooler. Thing is, vampire as disease isn't terribly sexy. Especially after Nick informs us that "the drugs don’t work, not forever. The only way to cure the disease is..." (drum roll, please) "...to kill the head vampire." Okay, maybe it's supposed to be some kind of CDC metaphor for Patient Zero or whatever, but it didn't really work for me, alas, since the whole must-kill-the-big-baddie is such a cliché.
Then there was the origin story, which make no sense whatsoever. According to Nick (who never tells us exactly how he found this out) eight French knights go into some horrifically bloody battle and must make a pack with Satan to survive. They eat one of their colleagues (as some sort of Satanic bonding ritual?) and become the first immortals with a taste for blood. They wake up the next morning so ashamed of their deeds that they hide from the light of day, and, what, I guess then are shamed into flames the next time the sun hits them or one of their offspring? (Talk about a bad blush! They don't just feel like their cheeks are aflame, they really ARE on fire!)
The disease metaphor gets completely forgotten, and people like me who think far too hard during action films, are left wondering, "So, then at what point is their bite an 'infection'? Who is the first infector? Satan? If that's the case, could these HIV drugs kill Satan? Is he corporal? Does the Ultimate Bad Guy even have blood? Shouldn't the local exorcist also want some of these HIV drugs to cast out other minor demons? Or was it the first guy they ate the one who was diseased, and if so, with what? Is vampirism our own Mad Cow disease fraught with the warning, don't eat other people, it will just lead to diseases that embarrass you to death?"
And when you start thinking like that, it ruins a perfectly functional action film.