In Naughty Dog’s The Last of Us video game, main character Ellie is immune to the cordyceps fungal infection that caused a pandemic that propelled the world into chaos and despair. Ellie is immune to the infection, but why, and how? The game never provides an answer, but the Season 1 finale of HBO’s series provides clues, it seems, to the origin of Ellie’s immunity. Spoilers for The Last of Us follow below.
In the Season 1 finale, we get a flashback that shows Anna (Ashley Johnson), pregnant with Ellie, trying to outrun an infected person, only to be cornered in an abandoned house and attacked. She kills the infected, and during the struggle, gives birth to Ellie. Anna is bitten during the encounter.
Anna cuts the umbilical cord, but the show leads us to believe the cordyceps infection was indeed spread to Ellie. Marlene (Merle Dandridge) soon arrives on the scene. Anna pleads with her to kill her and take Ellie, assuring Marlene that she gave birth before she was bitten–this is a lie.