The Last of Us: What is Cordyceps Infection and How Does it Work?

The Last of Us is probably the best video game adaptation in the history of streaming and television. Part of this is that the game has a very cinematic style and a story that is perfect to be told in the series format, where we will follow several survivors of an infection that ends millions of lives and forces the survivors to have to build new communities and face impossible situations. The story of the game and the series focuses on Joel (Pedro Pascal), a man who lived through the beginnings of the pandemic and becomes a smuggler to survive, and Ellie (Bella Ramsey), a teenager with a very special characteristic, which depends on Joel so that he can reach a safe place, where he can not only be safe from threats but must fulfill his destiny.

The series begins 20 years after the start of an infection called Cordyceps, which caused much more destruction than anyone expected, and remains one of the main threats facing survivors. Ellie and Joel, who are the heart of the story, are an important part of that story and, as those who have played video games know, that teenage girl could be a key element in changing the destiny of humanity.

The Last of Us: What is Cordyceps Infection?

According to the story of the game and the series (which is already one of the best of the year), Cordyceps is an infection where a kind of fungus attacks the human brain, and it spreads so fast that it destroys everything. Supposedly, humans begin to contract the infection after certain crops travel to different parts of the world, and part of the problem was that no one knew how to stop it or how to get patients to recover once infected. In a very short time, more than half the world’s population was either dead or infected by Cordyceps (named after a real fungus, but it doesn’t cause anything similar to what happens in this story), and it all takes place in 3 stages.

According to The Last of Us Fandom site, the infection proceeds like this: “Stage one begins within two days of infection, in which the host loses their higher brain function (and with it, their humanity), making them hyper-aggressive and incapable of two reasons or think rationally. Within two weeks, the host enters stage two of the infection, in which the fungus begins to impair their vision as a result of the progressive growth of fungus on the head and corruption of their visual cortex. After one year of infection, the infection enters stage three; scarring their faces and blinding them, causing them to develop a primitive form of echolocation to compensate. In very rare cases, if the host survives for more than a decade, it reaches stage four. They develop hardened fungal plaques over most of their body. When the fungus kills the host, the host’s body develops stalk-like fungal projections that release infective spores. The infection can also be spread through bites from live hosts. Hosts can only become infected while alive, as the fungus cannot infect cadavers due to its parasitic nature, although infected dead can release spores regardless of stage.”

The Infected aren’t exactly zombies, but they do have some characteristics in common, such as the fact that the living Infected can infect other people by biting them, which is part of why the infection spreads so quickly. In addition, also through the air (although not in rural or very open areas), through the spores, and this is why people must wear gas masks to avoid getting infected. And the scariest thing about Cordyceps is that there’s the real science behind all of this, it’s even explained at the beginning of the series when a scientist talks about a fungus that controls the brains of infected insects and forces them to spread it everywhere.

THERE ARE SPOILERS HERE, STOP READING IF YOU DON’T KNOW THE GAME AND DON’T WANT TO GET AHEAD OF THE STORY.

Is There Immunity to Infection?

Apparently, there are some people who can be immune to Cordyceps infection and Ellie (who is an orphan and was placed in an orphanage by Marlene, who belongs to the Fireflies resistance group) is one of them (and no, she is not a spoiler, even seen in the trailers for the series), which is confirmed after she is bitten and shows no sign of infection. It is possible that children, born after the start of the pandemic, have some type of immunity that has not been discovered. At the beginning of the chapter, we can see a boy arrive at the quarantine zone, who later appears in the pile of corpses.

We know they killed him because he tested positive, but, like Ellie, he might have been immune. According to theories, Ellie may have been exposed to the virus through her mother, who may have been infected while she was pregnant. This exposure allows her to fight off the infection and not develop any of the symptoms, which is why she is an important person to those who are studying the virus and continuing to search for a way to stop it.