Why Is Ellie Immune in ‘The Last of Us’? Answered

HBO’s The Last of Us has captivated audiences since January with its masterful adaption of the video game of the same name. The series and video game explore a post-apocalyptic world where an outbreak of Cordyceps, a parasitic fungal infection, has ravaged humanity. For 20 years, the virus has continued spreading as the bloodthirsty infected roam the planet and either kill or infect any survivors they come across. However, when a teenage girl, Ellie (Bella Ramsey), is discovered to be immune, a hardened survivor, Joel (Pedro Pascal), is tasked with taking her across the U.S. to a lab where her blood can potentially be used for a vaccine.

The majority of the game follows Joel and Ellie’s journey together as they come across infected, FEDRA members, Hunters, cannibals, and a few allies. However, in the midst of it all, a question that remains unanswered is how Ellie is immune to the infection. She discovers her immunity shortly after being bitten by an infected while roaming an abandoned mall with her friend and love interest, Riley (Storm Reid). The pair decide to keep fighting until the end. But the end never came for Ellie as days passed without her becoming one of the mindless infected.

Most individuals in The Last of Us are so amazed by Ellie’s immunity, they don’t question it. Many seem to just accept it as some kind of miracle. However, the nature of her immunity is definitely important. If it’s not just a chance genetic miracle, it could potentially be replicated.

How did Ellie become immune in The Last of Us?

In The Last of Us game, the cause of Ellie’s immunity is never explicitly explained. The closest it comes to an explanation is in the game’s epilogue, where a “surgeon’s recorder” briefly discusses Ellie’s immunity. The recorder definitely leans toward the miracle argument, as it describes Ellie simply as an anomaly. Scientists have never seen anything like Ellie’s body’s response to the virus, and they can’t really explain how she remains unaffected by the infection. The recorder also compares Ellie to the accidental discovery of penicillin. Hence, it seems like her immunity is just the result of random mutation.

However, one fan came forward with a theory that Ellie’s mother might be responsible for her daughter’s immunity. Ellie’s mother, Anna, is never seen in The Last of Us game but is mentioned. She was close friends with Firefly leader Marlene (Merle Dandridge) and worked as a nurse before becoming pregnant. Sadly, Anna died one day after giving birth to Ellie, but she wrote a letter to Ellie before dying. Therefore, she seemed to know that her death was coming.

One fan posited that Anna became infected right before giving birth to Ellie. In the game, those bitten have up to two days before they turn. So, it is possible that Anna had time to write a letter, give birth, and live for one more day before succumbing to the infection. The fan suggested that Ellie’s exposure to the infection while in the womb caused her immunity. It is an interesting theory. However, considering that Ellie was full-term, it is difficult to believe that being in her mother’s womb for one day after her mother became infected would somehow give her immunity.

While an exact explanation hasn’t been given, Anna (Ashley Johnson) is set to appear in HBO’s The Last of Us in the season finale. Anna will be part of an untold story from the game’s creator, Neil Druckmann. So viewers may yet receive a more satisfactory explanation of Ellie’s immunity in the finale.

(Featured image: HBO)