Keeping Potion Effect After Death (SOLVED)

I was wondering if there is a way to keep a potion effect post-death; 

for example, the mod im working on, allows the player to become a vampire, but if you die, it get rids of the effect, and then a player could easily switch sides, or avoid consequences.. I want to be able to make it a permanent thing, to avoid things like that happening, or players losing their abilities. For now, i have an object you can only get while being a vampire, that gives you (or another player) vampirism when consumed.