Or to put it another way: Is it still possible to write original zombie fiction? (Hint: The answer may surprise you.)
When the Night of the Living Dead was released in 1968, the concept of the zombocalypse was relatively original. The undead had certainly appeared in film and fiction before; but the notion of them taking over society was a new idea, indeed.
Almost 50 years later, no one can claim that the idea of zombies taking over the world is an original concept. There have been multiple installments of George A. Romero's zombie movies (many of them not very good, I should add). There have also been dozens and dozens of imitators, many of them even worse.
And yet, AMC was able to release The Walking Dead as recently as 2010 and find a wide audience.
In fact, The Walking Dead has become one of the most popular and acclaimed series on television. Even more significantly, it has gained an audience beyond people who describe themselves as "horror fans".
How can this be? There is, as noted above, almost nothing original about the premise employed here.
The mechanics of the zombie outbreak laid out in The Walking Dead are nothing that audiences and readers had not seen before 2010. In The Walking Dead, the zombie outbreak is attributed to a virus. Long before The Walking Dead debuted, a virus had already become the standard cause for the zombocalypse. A shadowy and sinister role for the US government and/or the defense industry had also become standard. And these elements, once again, all make appearances in The Walking Dead.
The lack of originality regarding zombies doesn't end there. The zombies in The Walking Dead behave exactly as you would expect zombies to behave, assuming that you've absorbed all the Romero movies, and all of the other books and films previously produced within this particular horror subgenre.
The zombies in The Walking Dead are driven by an irresistible urge to consume living human flesh. The only way to kill a zombie is to shoot it in the head.
Oh, and if one of The Walking Dead zombies bites you, then you'll turn into a zombie, too. Who would have guessed?
In short, the writers and producers of The Walking Dead made almost no innovations where the nature of zombies is concerned. They pretty much applied the boilerplate that had already been established by numerous other writers and filmmakers.
Yet The Walking Dead fully deserves its popularity. What is the show's "secret"?
The secret is a simple one, in a way--but also revolutionary, in a genre littered with clunkers like George A. Romero's Diary of the Dead (2007).
The writers and producers of The Walking Dead realized at the outset that it was no longer possible to create a completely original zombie, or an original zombie outbreak.
They therefore applied all of the existing conventions, and turned their attention elsewhere: They focused on telling compelling stories, peopled by compelling characters, all within the already established framework of the apocalyptic zombie outbreak.
This is why The Walking Dead grabs viewers, including viewers who ordinarily "don't like horror". No one watches The Walking Dead because the story premise is so original; it plainly isn't. Premise-wise, what we have here is old hat.
People tune in to The Walking Dead because they have become invested in the characters and their individual storylines. Viewers love Rick; they love Daryl; they love Maggie. They care what happens to them.
And in this regard, The Walking Dead stands above most of its zombie genre competitors by meeting one gold standard: The Walking Dead would be a fairly decent and watchable show even if there were no zombies, because the characters are so vividly drawn, and the subplots are so multilayered and believable.
This is what makes The Walking Dead "different". And this is the technique that you can use as a writer when working in any well-trodden genre with many set elements and conventions.
Sometimes it is simply impossible to create an entirely new, never-imagined-before premise inside a genre.
So what does the writer (or filmmaker) do? Hook the reader (or viewer) with characters and stories that appeal to them even in absence of the standard genre elements.
Which brings us to the status of genre fiction in the literary universe. It is no secret that genre fiction receives little respect among general readers.
This isn't because most people are inherently opposed to reading about zombies, serial killers, and spaceships. The problem is that too many genre writers get so caught up in the zombies, serial killers, and spaceships that they forget the fundamentals of good storytelling and strong character development.
Let's now return to our opening question: Is it still possible to write original zombie fiction?
If you define "original" as completely original zombies, then the answer is: probably not.
But complete originality of the background premise should not be your goal, as it is probably unrealistic.
(Novelists in the romance genre understand this principle. There is no truly original boy-meets-girl, boy-loses-girl, boy-gets-girl-back novel. All romance writers rely on the same basic structure.)
The proper goal, for the zombie fiction writer, is to write an original story, with original and well-developed characters, that would stand on its own legs even if it contained no flesh-eating zombies.
(Note: I'm not suggesting that you should write a zombie novel without zombies. I'm suggesting that a strong zombie novel (or film) doesn't rely only on zombies.)
This strategy worked well for The Walking Dead If your goal is to launch another zombie novel into an already crowded marketplace, this strategy will serve your purposes, also.