Here's something weird. Last week, without talking to each other, my sister and I both happened to randomly browse our individual library's teen section, stumble upon the book Peeps, by Scott Westerfeld, and both checked it out. It's a good book, so we both read it last week. We discovered on Sunday that we had both read it at the same time...kind of spooky!
Anyway, Peeps is a fascinating twist on vampirism. And before you say anything, let me add: I do not usually read vampire books, so for me to have liked this one says something. Vampirism is actually a parasite, and it's spread by saliva or sexual contact. (And with that, realize that Peeps would probably be rated pg-13.)
I highly recommend this book, and in fact, I'm planning to read anything I can find by Scott Westerfeld. He's brilliant!