Well, depends on the setting, but for the MCU? Yeah, the setting isn't really compatible with having that many vampires. Outside of maybe some eastern european occult hellhole ( *coughTransylvaniacough* ), vampires should be damn rare. Rare enough that mundane secret organizations like SHIELD or Hydra would plausibly either be unaware of their existence, or only aware of them as some vague and unimportant oddity. Which means there should probably be less "vampires" and more "individual specific name vampires and perhaps their circle of underlings".
Of course, this status quo can always *change*, in the present. Maybe while there used to be only a few dozen vampires on the entire planet, now something has changed. Sleeping vampires are waking up, old vampires are now more powerful, and everyone finds it much easier to make new vampires. Like, say, because the dimensional barrier shielding Earth from hostile otherworldly powers got totally collapsed for a brief time.
