The Last of Us Season 1 finale may have divided viewers, as it seemed to explain why Ellie was immune from becoming completely infected, as Episode 9 aired on HBO and became available to stream on HBO Max. Some fans enjoyed the fact that Ellie’s immunity was never completely explained, but it appears as though the reasons behind her immune status have now become canon. Here’s what happened.
Why is Ellie immune from the cordyceps infection in The Last of Us?
Ellie is immune from the cordyceps infection because her mother Anna Williams was bitten while giving birth, just before cutting the umbilical cord that connected the pair. Marlene explained to Joel in The Last of Us Episode 9 that “normal cordyceps think that she’s cordyceps,” because the infection within her body has “grown with her since birth.”
Many have theorized in the years since the Naughty Dog game on which The Last of Us HBO series is based that something along these lines would be the reasoning behind Ellie’s immunity, but this is the first time that it has been explicitly confirmed. It begs the question, if other mothers were bitten during birth, could there be other children and young adults like Ellie who are immune, or was she the exception to the rule?
While Marlene wanted her doctor to push ahead with brain surgery, removing the “chemical messenger” from Ellie and attempting to mass-produce it in a lab, this would have killed her. Joel wasn’t willing to let that happen, no matter the price, and so blasted his way through the hospital, rescuing her from the operation and slaughtering several Fireflies in the process.
Joel’s lies to Ellie about what happened in the hospital and his actions may come back to haunt him when The Last of Us Season 2 debuts on HBO and HBO Max.