they're fictional creatures so they have whatever diseases the creator of the particular story they're says they have or don't have, or if they don't specify at all we can assume they don't as it's not relevant to the story about the monsters
Vampires can't get diseases due to the organism living inside them that is impervious to all disease & viruses. Their white blood cells have mutated due to the organism that is using their bodies as a host & cannot be penetrated by HIV. HIV cannot replicate or reproduce & dies in the vampire's body.
Vampires are able to drink any blood but they prefer healthy human blood. Contaminated or diseased blood, while it won't affect them, does not taste good to them.
Or you know, spirits can't get diseases
Not all vampires.