Oh man, this question takes me back. I devoured the first few books ages ago. 'Aurora Sky' is about a girl who gets brought back to life after a car accident, but now she has this weird vampire-hunting blood—like, her blood is literally poisonous to vampires, so she gets drafted into this secret government agency. She's sent to infiltrate a bunch of vampires in Alaska, which is a pretty cool setting, and has to pretend to be this college student while actually hunting them. It's a whole secret life, double-agent thing.
I remember the tension between her and one of the vampire guys, Fane, being a huge draw early on. It gets messy fast because of the whole 'I'm supposed to kill you but also you're kind of hot' dynamic. The plot gets into vampire politics and a bigger conspiracy behind the agency itself as it goes on, which I thought was neat.