For obvious reasons I think it's important that any religious symbol can repel vamps

A lot of vampire lore strikes me as... "administrative" in nature. The aversion to specific symbols. The counting of grains of rice. The sleeping in dirt from their homeland. Inability to cross running water. It's all very rules-based.

Also, just as I like the idea that sunlight doesn't strictly KILL vampires but just "de-animates" them, I like the idea that holy symbols deal psychic damage to vampires instead of physical. I think it was Fred Clarke who suggested that religious symbols create massive cognitive dissonance in vamps