And in settings with where "vampires are often shown showing vulnerability only to Christian symbols," it is not "the power of belief that invests a symbol with power," but the power of God.
Also, the folklore surrounding the manananggal, the ramanga, jiang shi, etc. obviously don't apply here: It's Dracula.
I am just saying that "faith" being what repels vampires is just a multicultural interpretation of the more traditional folklore. It is traditionally God, which means only crosses/crucifixes warding vampires makes sense in those stories. There isn't a more true interpretation to "acknowledge".