ZOMBIE movies have zero credibility. Generically they have scant variation. A bunch of the undead feed from those not yet reduced to that condition.

Undeadness is selectively contagious. A pretty girl bitten by a handsome zombie boy will become a zombie and vice versa. Unattractive humans bitten by zombies die in agony from extravasation.

In “World War Z”, directed by Marc Forster, from a novel by Max Brooks, adapted by a writing team led by Matthew Michael Carnahan, zombie recruitment is spreading globally from an unknown origin.

Today it’s arriving in downtown Philadelphia where Brad Pitt, playing a retired UN peace-keeping troubleshooter, makes a vehicular charge through gridlock to get picked up by a helocopter and taken to an offshore naval ship from which, in exchange for protecting his wife and kids, he accepts a gig to travel by government aircraft to seek a cure for zombieism.

In South Korea, the scientist accompanying him gets bitten. In Israel, he has to perform a field amputation of the left hand of an attractive sabra before the zombie venom envelops her body.

Armed with a theory that might lead not to a cure but to a prophylaxis, his next flight is to Wales where he survives an airliner crash to reach a WHO research center where supplies of the necessary nostrum are held in the wing already occupied by zombified staff.

The film’s reputed budget is $US170 million. Whether the zombie genre has a big-enough fan base to recover that is a moot point. The fan base of Brad Pitt, who co-produced it, may save it financially. Artistic salvation? Improbable.

 At Hoyts, Dendy, Capitol 6 and Limelight