French filmmaker Julia Ducournau has channelled personal emotions and collective trauma into her new drama, 'Alpha' that centres on an unruly teenager navigating a world gripped by a virus that turns patients' bodies into marble.

Best known for her Palme d'Or-winning body horror 'Titane', Ducournau's latest features 13-year-old Alpha (Melissa Boros) gets a tattoo from a potentially contaminated needle at a house party. Her mother (Golshifteh Farahani) panics over the risk of infection, and Alpha soon faces rejection at school.

Ducournau, who wrote and directed the movie, said the story reflects a "dark cycle" in current world events, intertwined with memories of the AIDS pandemic in the 1980s and 1990s, though the film is not about AIDS.

"I felt that these emotions I'm experiencing every day—the knot in my stomach, the tears stuck in my throat—needed to be addressed," she said. "The only way to do that was to transfer them to another period of time where I felt born into a world doomed to die. The biggest thing I wanted to talk about is the spread of fear and how it generates rejection and hate. If it's shocking for a fictional young girl, why isn't it shocking in real life?"

'Alpha' also features 'The Prophet' star Tahar Rahim as 'Alpha's uncle Amin, a drug addict re-entering her life. Rahim underwent a dramatic physical and mental transformation, losing more than 20 kilograms for the role and working with a charity supporting drug users.

Participating in outreach rounds and spending time with users helped him understand addiction, which informed his performance. "I felt like someone in his own lab, experimenting to see if it blows up or not to create something," Rahim, 44, said.

"It's one of the best experiences in my acting career, but also in my personal life, because I felt wide open and could sense everything surrounding me." Alpha is set to open in UK cinemas on Friday.