"Anyone remember that Will Smith movie I am Legend? Those weren't dead people, those were infected live people. (I'm going by the movie not the book. I don't know what happened in the book or how everyone turned into vampires/zombies in the book)"
They are vampires in both the book and the movie, although this doesn't matter as a zombie is simply a vampire with no thought process or ability to think for that matter.
You should read the book! The book and movie both have different plots so you aren't spoiled about the book's plot if you have seen the movie. It's pretty depressing, although not nearly as sad as the scene where Neville puts down Sam in the movie.