Quote from Mead's blog about Bloodlines:
"Bloodlines is the spin-off series to Vampire Academy (it's the name of the first book and of the series). It's set in the VA world but will be about different characters: Sydney (our narrator), Jill, Eddie, and one of the love interests from VA. I'm not saying who that last guy is, but it's mostly to protect those who haven't read Last Sacrifice. If you have read it, then it should be pretty obvious who the other character is."