but id call him an expiriment but the expiriment gave him some vampiric aspect but also have him the power to change his form.60-70%human and 30-40% expirimented shapeshifter.the only reason that they consider him a vampire is his coffin and the way he dresses.so if you think about it he is not a vampire at all.
EDIT:on second thought vincent can only shape shift because of the cells implanted in him which makes him about 99%human1%monster.