I enjoy playing Dawnguard and being a vampire hunter. However, I also use a mod that adds higher tiers of vampire baddies that are very difficult to kill.

I would like to create a mod that adds some vampire-specific poisons to the game, but am unsure how to get around vampire poison immunity. Any thoughts on how to do this?

If I remember right there's a weakness to poison poison... And there is hopefully a weakness to poison spell. If you could make a weapon that applies a custom enchanted 100% weakness to poison effect, I believe it would override their 100% poison immunity, hope that helps... As they are immune to poison but not magic.

Why not just use fire and shock enchantments? Vampires are vulnerable to fire. Just get a fire weapon that does up to 68 fire damage. Shouldn't be hard.