How Is Ellie Immune to Cordyceps & Why Didn’t That Bite Affect Her?

Ellie’s immunity to the Cordyceps infection is the driving force behind The Last of Us, but how exactly does her body resist the fungus that destroyed humanity? While the HBO series has teased her resistance since the beginning, The Last of Us Episode 9 revealed the truth behind her unique condition.

But how exactly is Ellie immune to Cordyceps, and why didn’t the Infected bite turn her in The Last of Us? Here’s a lowdown on the same.

How is Ellie immune to cordyceps in The Last of Us Season 2?

Unlike other survivors in The Last of Us, Ellie’s immunity to the Cordyceps infection isn’t luck. It’s a fluke of biology, and the key lies in her birth.

In The Last of Us Episode 9, a flashback reveals that Ellie’s mother, Anna, was bitten by an Infected while in labor. Before turning, Anna cut the umbilical cord, but not before the Cordyceps fungus entered Ellie’s system. However, instead of turning her, the infection mutated in a way that protected her.

As Marlene later explains, the Cordyceps in Ellie’s body acts as a “chemical messenger.” When new spores enter her bloodstream, like from a bite, her mutated version of the fungus tricks them into thinking she’s already infected. This stops the disease from spreading to her brain, making her the only known immune survivor.

Why the Zombie bite in The Last of Us Season 2 Episode 1 didn’t affect Ellie?

The Last of Us Season 2 Episode 1 introduces a new version of the Infected called the Stalker. This advanced stage of infection moves on all fours, stalking prey with eerie patience. Unlike Runners, who charge blindly, or Clickers who rely on echolocation, Stalkers are cunning.

This Stalker follows Ellie silently through dark aisles before ambushing her later. After a brutal struggle, Ellie finally kills the zombie, but not before it sinks its teeth into her. However, it doesn’t infect her due to her immunity.