Speculation on how Vampires would fit into the MCU without the general public becoming aware of their existence.
Have the spell that created the original vampires have a "Runes of Kof-Kol" type effect for all vampires (both the originals & their descendants).
Vampires in the MCU would function like the "The Silence" from Doctor Who with the exception being people who were fed upon (but not killed) would be able to permanently remember vampires but no one else would.
The act of feeding creates a mystical bond between the vampire & the victim.
I would even enhance the effect so that anyone who hasn't been fed upon would actively disbelieve you.
Blade, like all vampires would be immune to forgetting (he always remembers), & the spell also keeps the general public from becoming aware of Blade's actions (such as killing vampires in public).
Have the "Nightstalkers" be comprised of humans who have survived vampire attacks & can now remember them. So, they band together as vampire hunters.
I would have the spell continuously alter any video, photo, drawing, & sculpture of a vampire to become distorted shadowy silhouettes, & any written reference to vampires becomes vague, cryptic & filled with inaccuracies.
Nightstalkers get around this limitation by writing journals using the one thing the spell doesn't tamper with, they write their journals using their own blood.
Their mystic bond between vampires & their victims is blood based, writing using their own blood is unaffected by the spell.