Besides Spellcaster's (excellent) point, "strong as a vampire" is sort of vague. It's not like there's some measuring system we have for aural integrity or spellcasting intensity. And even if there were it isn't like vampires, or anyone else, are of some identical form and strength.
Try making specific goals you'd like to reach. What /specific/ feats of vampiric strength are you hoping to be able to accomplish?