vial of blood and Vampirism

[freakna]

So for the longest time I've used vial of blood to become a vampire for the regening at night but its not working anymore. I tryed quaff vial and it just says witch disease do you want? So I try quaff vial Vampirism. Well that didn't work. So can anyone tell me what am I doing wrong or did the vials of blood change and no longer for Vampirism.