Boyle and Garland have both acknowledged Romero, while being careful that these are not zombies but the living infected. What carries over is Romero's whole argument rather than his monster: the dead are the setting, and the film is about the survivors turning on each other indoors. The soldiers at the manor house are 28 Days Later's version of the posse who shoot Ben. Boyle has also named The Day of the Triffids for the empty-city opening, which is why this is MEDIUM rather than HIGH.