Rod Hardy’s Thirst (1979) is an Australian horror gem blending vampiric mythology with cult control and medical experimentation. Chantal Contouri stars as a modern woman abducted by a secret blood-drinking elite who claim she’s a descendant of Countess Elizabeth Báthory. Chilling, sterile, and stylish, Thirst merges vampire lore with psychological manipulation and 1970s clinical dread — a cerebral entry in Ozploitation horror history.

Powerhouse Films

Chantal Contouri (Snapshot), David Hemmings (Harlequin), and Henry Silva (The Tall T) star in Thirst, a shocking fusion of horror and science fiction from legendary Australian producer Antony I Ginnane (Patrick).

A sinister organisation known as the Brotherhood kidnaps Kate (Contouri), believing her to be the descendant of Countess Báthory, the Hungarian noblewoman who reputedly had vampiric tendencies. A battle of wills ensues as the Brotherhood tries to force the horrified Kate to join their blood-drinking sacrificial cult. Only Dr Fraser (Hemmings) is willing to help her... 

Directed by Rod Hardy (Nick Fury: Agent of S.H.I.E.L.D.) and with a score by Brian May (Mad Max), Thirst is a classic of Ozploitation cinema.

Från IMDB:
The descendant of Elizabeth Bathory is abducted by a cult of blood-drinking, self-proclaimed supermen who want her to join them.