It's not explicitly vampires. The setting is modern day Chicago but in a world where magic and magical creatures are real. Mainstream society doesn't know about them, though, so they stay in denial while the weirdos stay undercover. Well, mostly undercover.
Harry Dresden is a wizard, one of perhaps two dozen powerful, professionally trained wizards in the U.S. He also has an add in the Chicago yellow pages under "wizard". He's basically got a P.I. vibe going and is called in by the cops when the supernatural world rears up into the light a bit too much.
There have been books focusing on vampires (there are three or four kinds, none of them nice), but most of them deal with other subjects. If he liked early Hamilton for anything but the sex or the "vampires are so great!" aspect, then he'll probably dig these.