Are vampires shape-shifters

No, your basic vampire is actually quite a pathetic creature, capable of stealing life-force and that's about it. The ability to shape-shift was one of Count Dracula's many abilities - not because he was a vampire but because he was a high level sorcerer, having attended the Scholomance in the Carpathian Mountains. Due to his fame the ability has become sort of a stereotype in the more pulp-level fiction.