The origins of the Wildfire Virus is one of the biggest mysteries of The Walking Dead that will likely go unsolved forever. The virus quickly became a pandemic by killing people and then reviving a small part of their brains, allowing them to rise as zombies (known as “walkers”). But who was the first person to be infected by the virus?

The contagious disease was first introduced in the flagship series and explained in detail during the CDC episodes of Season 1 and in the Season 2 finale when Rick Grimes revealed that every human is infected. The virus doesn’t just spread through a bite wound by another walker — no matter how a person dies, if the brain is still intact, they’ll come back as a walker. Before Rick and his group of survivors learned this, Fear the Walking Dead‘s Clark family already had the inside information from experience.

Updated on March 4, 2024 by Katie Doll: The Wildfire Virus is still an enigma in The Walking Dead franchise. It’s unlikely any current or future spinoffs will ever answer who Patient Zero was, but one can only hope. This article has been updated to expand more on the known background of the Wildfire Virus and the possible candidates for Patient Zero.

The History of the Wildfire Virus in The Walking Dead

The Wildfire Virus

Creation
Created in 2010 by the Primrose Team in France for vague experimental reasons.

First Victim
Still unconfirmed, but the first person on-screen in the TWD timeline universe to be infected is Gloria on Fear the Walking Dead.

Infection
The entire human population is infected by the airborne virus, but it doesn’t activate until a person’s death. The virus can be triggered through a walker bite, which precipitates a deadly fever and bacteria. Once dead, the person reanimates into a cannibalistic being within 2 minutes to 48 hours.

Variants

Lurkers and roamers
Climbers
Burners
Cohorts
Hybrids
Walker King

Cure
No known cure, but walkers can only be killed by destroying the brain. Amputating a limb with a walker bite in time can prevent spread of infection.

The Known of the Origins of the Wildfire Virus

Scientists May Have Created the Virus Accidentally

Every spinoff since The Walking Dead‘s finale has fed breadcrumbs of new information about the origins of the Wildfire Virus, hopefully leading to confirmation of who Patient Zero is. The virus was initially an airborne infection that remained inactive until entering a human being’s body. Since the first person was infected, whomever they were, the virus has reached new levels of being transmitted through bites. Additionally, because the virus was initially airborne, everyone in the world is technically “infected” — the virus just doesn’t activate until a person dies.

The virus is believed to have been created by the Primrose Team in la Biomédicine DDMI in France in 2010, but for reasons that haven’t been specified. Theories have circulated that scientists were experimenting with new treatments for diseases but ended up creating something more diabolical. Being its place of origin, France was one of the first countries to experience the wrath of the virus. Paris fell into chaos overnight, with no warning to help its citizens evacuate or reach safety. Variants unheard of in America were created in France, such as flesh-burning walkers. Airborne viruses as dangerous as this one are more than likely to spread to other countries via travelers who are unaware that they’re infected. Given these conditions, this was probably how Los Angeles and other cities in America were roped into the pandemic.

Fear the Walking Dead Suggests the First Walker Is Gloria.

When Fear the Walking Dead premiered as the first TWD spinoff in 2015, actor Lexi Johnson referred to her character, Gloria, as “Patient Zero” of the zombie apocalypse. Gloria was Nick’s girlfriend, who first appeared in the pilot episode as a walker and in a future episode in flashbacks. The pilot opened with Nick waking up in an abandoned church where drug users often went to get high, only to find that Gloria was eating another person. It’s assumed that she died from a drug overdose, but there’s also a knife wedged in her chest, which was presumably done in defense by one of the people she killed.

Gloria somewhat became an iconic symbol of Fear the Walking Dead, much like Bicycle Girl and the little girl walker did in The Walking Dead‘s pilot episode. Gloria was the first walker to appear in the spinoff and is chronologically the first on-screen TWD walker. But due to the circumstances of her death, Nick’s fear of the world falling apart wasn’t shared by his family until they saw the dead coming back to life for themselves.

The Walking Dead’s Patient Zero Is Still a Mystery

Although confirmed by Johnson, there’s canon evidence that Gloria probably wasn’t Patient Zero in The Walking Dead universe. The next spinoff The Walking Dead: World Beyond hinted that the Wildfire Virus was created in a lab in France and wasn’t discovered by the CDC until April 2010. Considering Gloria didn’t overdose until August or September of that year, there’s a high chance that someone else died of the virus before her in Europe at the very least. It certainly supports Dr. Edwin Jenner’s claim that it had been 194 days since the first report of the virus when Rick’s group visited the CDC. There were also many unconfirmed cases of the new “illness” going around the country in the pilot episode of Fear the Walking Dead, which a student named Tobias was already well aware of.

The idea of Gloria being the first walker might’ve been true back in 2015, but since then, so many details about the virus’ origins have been exposed. If anything, The Walking Dead: Daryl Dixon could show the origins of the real Patient Zero, as the series advances more into experimental territory in Season 2. The flashbacks of the initial outbreak in France in Season 1, Episode 2 refused to delve into the Patient Zero case, but the Power of the Living are gaining more traction with their walker tests. Why are they even doing the experiments in the first place? Possibly because they know how it first started. The Ones Who Live can also tap into the Patient Zero theory now that Rick Grimes and Michonne are intimately involved in the CRM, who have an egregious history of using rudimentary methods to find a cure. It’s undeniable that Gloria is the on-screen Patient Zero in The Walking Dead universe, but off-screen is an entirely different mystery that has yet to be cracked.

The Walking Dead and its companion series are available to stream on AMC+. Additionally, The Walking Dead is streaming on Netflix.