"New Blood" as a stand alone title appeals to me as it is quite story specific and the answer to the story problem. It becomes problematic only when associated with vampire stories, which it is at New Concepts, so be very careful in choosing your title and take into account where it's going to be marketed.
My first book, "Mitchell's Run", began life as "High Plains Ghost" until I realized that the property called "Mitchell's Run" (Run is an Australian term for an outback rural property, a ranch) was the driving force behind the story. When rewritten for its American release, It became "Mitchell's Valley".
I aim for two things in choosing a title, brevity and aptness. Like the closing words, I want it to resonate in the reader's mind so they'll look at my next title with appreciation for the care taken in choosing it.
Which is why I was reluctant to change "New Blood".