... to pile on onis idea...
Vampirism and magic are both.
Vampires are born pure bloods, stronger, faster, powers are more under control, and dont get hit with the thirst as hard as the are born with it, they learned control growing up and their systems are better adapted. While turned are second class of vampires, not treated like trash, but nkt as valued, overlooked for prospects, ect, as they arent as strong.
Mages come in the same. Born mages, their bodies more capable of handling magical energy thus can throw power like there is no tomorrow, and learn discipline to use them from younger age, where "anybody" can learn magic, provided they stick with it, but they cant channel as well so tire out fast, dont have the discipline, or know as many spells.
War is cold war between vamps and mages, smiles and catty comments in public, fangs, fire, and folly in private, mainly kept on by bloodline mages and vamps giving orders to lowers while promising rewards.
Maybe both sides thinknthey are protecting humanity?
Mages are stopping vamps from turning humans into mindless cattle for them to feast upon, and while cant teach them all magic, can "intiate" them to help with rituals or such. They lend extra will, power, and so forth.
Vampires are stopping mages from turning humanity into mindless cultists as they make contact with thigs best left alone, yeah, they feed on humans, but they like humans! The whole "im not a man, im a monster!" angsty crap is so gauche. They dont need to kill, amd save for a few psycho/sociopaths nobody really gets enjoyment from it. Happy healthy ad free humans produce richer more vibrant blood, and pretty much any vamp can go out to get "something to eat" with no problem.
Turns out they are both just really shitty racists to each other.