The curse of vampirism back home on Toril, on the supercontinent of Faerun doesn't make for good company, let's just say that lol.  They can turn into bats, mist, and crosses themselves don't necessarily work, but the holy power of a cleric however does when used by one with faith.  Not so sure on garlic and silver, would have to check my DnD books on the matter.  It doesn't matter here of course given it's a different world, different rules and all that lol.