The Last of Us Finally Reveals How Ellie Is Immune

The last episode of Season 1 of HBO's The Last of Us has finally revealed how Ellie (played by Bella Ramsey) is immune to the infection that has spread across the globe. Ellie's immunity against the fungus that has plagued the world of The Last of Us has been a key component of both the video game series and the HBO adaptation. And while the games never shed much light on how Ellie was able to keep herself from becoming infected, the show has now finally given fans a long-awaited explanation. 

How Is Ellie Immune?

The way in which Ellie is able to keep from turning into an Infected fungal monster for herself in The Last of Us dates back to her own birth. The opening moments of Episode 9 of The Last of Us reveal Ellie's mother, Anna, and show her giving birth to her daughter. At the time of Ellie's birth, Anna had recently been attacked and infected by a creature herself. When Anna was infected, Ellie had just been born and was still briefly connected to her mother before Anna severed the umbilical cord that connected the two. 

As a result of Ellie being born via a mother that was briefly infected by the Cordyceps fungus, Ellie's body gained immunity in a rather odd manner. Explained by Marlene in Episode 9, Ellie's body was able to produce a "chemical messenger" following her birth that tricked the fungus into essentially thinking that she was part of the Cordyceps already. As such, the fungus never took control of her body as it has with countless others in The Last of Us.

In short, because of Ellie's unusual circumstances surrounding her introduction to the world, she has been able to remain immune for her whole life. Better yet, the Cordyceps fungus has been existent in some capacity within her body since mere moments after her birth. So while she previously thought that the Infected creature that bit her and her friend Riley in the mall marked her first run-in with the Cordyceps, it turns out that the fungus has been lying dormant within her for her entire life. 


For more on The Last of Us, be sure to check out The Last of Pods podcast which features weekly breakdowns, reviews, and interviews centered around the ongoing HBO series.