Summary
After the latest episode ofThe Last of Usmade a pretty definitive statement about whether the Fireflies could have made a cure, series co-creator Neil Druckmann has settled the long-running debate.
The Last of Us is made up of many incredible and memorable moments,but by far the most important in the whole series is when Joel chooses to murder the Fireflies to save Ellie’s life, taking a chance at a cure away from the world. It’s a defining scene for Joel’s character that has a massive ripple effect throughout the rest of his, Ellie’s, and Abby’s stories,and one that’s talked about to this day.

In the game, one of the key reasons why this choice is so debated is that it’s left fairly ambiguous as to whether the Fireflies could have even made a cure by sacrificing Ellie.Fans have discussed the likelihood of one biologist being able to create a curefor such a humanity-ruining virus, something that the show recently made up its own mind about.
Yes, The Fireflies Could Have Made A Cure In The Last Of Us
Joel’s Decision Really Was World-Ending
During the latest episode of Season 2 of The Last of Us, Joel and Ellie’s beloved porch discussion was adapted and combined with the scene where Joel confesses what he did to the Fireflies.Ellie point-blank asks him whether the Fireflies could have made a cure out of her, which leads to Joel nodding his head yes as if he knew that a cure was possible.
This was a big moment for fans, since the games never really confirmed whether a cure was possible and left it up to your imagination.As pointed out by ResetEra user Antoo, series co-creatorNeil Druckmann has confirmed in a recent interview with Sacred Symbolsthat Naughty Dog always intended for players to believe that a cure was possible.

When asked about the whole debate, Druckmann said that, while the “science is shaky”,the intent from Naughty Dog was always that they would have made a cure by sacrificing Ellie. This made Joel’s choice a “more interesting” one from a philosophical viewpoint, as it means that he really made the choice between Ellie or the world.
All I can say is that our intent is that they would have made a cure. That makes it a more interesting philosophical question for what Joel does. - Neil Druckmann
Druckmann’s comments on the debate still leave a little breathing room, butconsidering he also directed the episode of the show where Joel said that a cure could have been made, it does seem pretty set that it was possible.