The Last Of Us Episode Two helps explain why Joel didn’t get infected

Without specifically spelling it out, the first two episodes help explain why some got infected immediately.

Spoilers for the events of the first two episodes of The Last Of Us. The show adaptation of The Last Of Us is filling in a lot of interesting backstory that the video game version obviously couldn't quite get round to, what with all of the gameplay stuff it needed to include in order to... y'know... be a brilliant game. In the first episode of the show, we're told that within the post-breakout world, the virus is spread by bites from tendrils within the mouths of the infected. But what we weren't told is how the infection began in the first place. The pre-credits scene in that first episode, featuring a decades-old interview with a scientist (John Hannah), explained the conditions in which the virus might be able to be created... specifically, global warming. Which, as most scientists now agree, is a very real thing. During the pre-credits scene in the second episode, we actually get to see ground zero for the outbreak. A scientist is snatched by soldiers in Jakarta, Indonesia, and brought to a lab where she gets to examine recently deceased infected. The soldier informs the scientist (and us) that the infection appears to have originated in a flour factory, which the scientist calls a "perfect substrate". Which basically means, flour is the ideal carrier system for the virus to piggyback on to. When asked what they can do to help slow down the spread of the infection, the scientist emotionally demands that they bomb the entire city of Jakarta, before asking she be allowed to go home to spend her final hours with her family. Which, in and of itself, was an absolutely terrifying interaction. Now this information will shine a new light on the details from events within the first episode. When Joel and his daughter Sarah see the elderly neighbour (who will eventually become infected before the day is through), we see she is being fed biscuits by her caring husband, as he implies it is the only thing she'll eat anymore. So... that is a lot of flour. But also, throughout that day, Joel begins the day by attempting to make pancakes (full of flour), but they're out of pancake mix. Sarah visits her elderly neighbour during the day, and when she is offered a cookie (full of flour), she turns it down. And later that night, Joel forgot to pick up a birthday cake (full of flour) for his at-home celebrations. So it is very likely that the infected batch of flour was already in mass circulation, but because both Joel and Sarah (and whoever else around the world) successfully and/or accidentally avoided a lot of flour consumption, they missed out on being naturally infected by the virus. Episode Three will be available to watch on Sky Atlantic and stream with a NOW Entertainment Membership from 2am on Monday, 30 January.