Female Vampire (1973)

Countess Irina of Karlstein resides quietly in a hotel on the island of Madeira, where she sustains her immortality by feeding on the life essence of men and women. When new victims are found fatally drained of potency, forensic scientist Dr. Roberts consults his colleague, Dr. Orloff, who confirms that a vampire is responsible. Meanwhile, Irina is confronted by a poet who believes he is destined to become her lover and join her among the immortals!