The zombies are back, big time, Friday with “28 Years Later.”

This franchise reboot follows “28 Days Later” (2002) and “28 Weeks Later” (2007) and marks the return of director-producer Danny Boyle, screenwriter Alex Garland (“Civil War”) and cinematographer Anthony Dod Mantle, all of whom worked on the original.

“We wanted to surprise people with a return to this world. The time passing gave us that surprise,” Boyle, 68, said in a Zoom interview from London last weekend.

“The 28 years is 23 years in our reality,” he conceded. “To make it 28 years is comfortably acceptable — and sets the premise for what you’re going to look at. It gave us new characters and also the premise: What’s happened to the survivors over 28 years?

“How have people evolved in a life without electricity, without technology? Even more interestingly: How has the virus survived?

“Because it’s clear at the end of the first film, it’s going to die out very quickly. But of course, the virus has learned, as viruses do, to mutate, to change. That changes their behavior. We see that they learned to hunt — that implies that they’ve organized.

“Because you can’t hunt deer on your own: You have to work like animals work — in a pack. Do that, then leaders emerge — another stage of evolution. Out of that, an Alpha emerges.

“That evolutionary chain means that you can set up a film that exists on its own. You don’t have to have seen the first movie. It also gave us the starting point for a story arc that stretches over three films eventually.”

At the center is a family — Aaron Taylor-Johnson’s Jamie, a hunter, his seriously ill wife Isla (Jodie Comer) and their 12-year-old son Spike (Alfie Williams) — eventually joined by Ralph Fiennes’ doctor.

The kinetic energy of the hunted vs zombie hunters propels “28 Years.” Rated R for graphic nudity means a naked zombie horde, their privates on parade. Were there ratings/censorship issues?

Boyle laughed. “There is an extraordinary story here, which is when we started prepping the film (where you have meetings with the different departments), we met with the intimacy coordinator.

“She said, ‘You know you’re not going to be able to use any nudity if the boy is in the area.’

“I said, What? She said, ‘Presumably a lot of your infected are going to be naked, because any clothes they had would have disappeared over time. But it’s an offense under the British Child Sex Offenses Act to have anybody under the age of consent in a room with male or female adult genitalia.’

“So,” Doyle confirmed, “every bit of genitalia you see, the privates that you see? They’re all fake. Prosthetics! All of them!”

“28 Years Later” opens Friday