When Jay leaves Vault 81 with Piper and Curie, maybe they’re all a little worried because they all know Jay’s been bitten - he was cleaned and bandaged right there in the Vault, and the arm looked red and unhappy.
And they get ready to spend a night in this abandoned house on their way to wherever they’re going from there, and Piper has first watch but Jay isn’t sleeping yet either. And Piper asks: what if you get what that kid had? She doesn’t say: You could DIE. What if you DIE? but they both know what she means. (Curie doesn’t necessarily help - ‘there is no pre-existing data on the effects of the disease on people outside the vault, I do not really know what will happen.’)
And Jay’s quiet for a bit, and then almost laughs: then I’ll get sick. And if... if it kills me, then I die having saved a little kid’s life. I can make my peace with that.
And of course he does get sick - has a fever that rises dangerously high, muscle aches and spasms, headache, nausea, the works, and he doesn’t get better for almost a week. He has Curie and her friends looking after him, and Curie knows about the disease and can treat him even without the cure, keep him hydrated and comfortable and the fever from burning his systems, but he still half-expects to die. He doesn’t know if he’s ever been this sick before (he has been, when he was a kid, but he doesn’t remember it, just that he had to stay in a hospital for a week). He’s not happy about it, but he’s too tired to grieve, or to really be afraid.
And then he fights it off and gets better. His immune system is more used to fighting off unfamiliar intruders than anyone’s in Vault 81 and he’s already had a little time to get a little better used to the Commonwealth variants of things as well (I imagine the first few months were just Jay getting every common thing ever - cold, stomach bug, you name it).
Of course the way the molerat disease works, he never really kicks it, and occasionally manifests as chills and muscle aches and light fever, headaches and sleepiness (’Jay’s been extra nappy, must be the molerats flaring up again’) but never again anything that dramatic. Just a chronic reoccurring nuisance, and an extra reason for Jay’s reckless napping. Not that he needs one, necessarily, he doesn’t sleep very well most nights, but you know. ;u;
And maybe eventually Curie is able to recreate the cure, or create a new one and Jay can be rid of the damned thing, but until then? He’s fine. Mostly.
