So I got a theory about Trevor's immunity this afternoon... What if he's unaffected by the Refractor because he's a carrier? I mean, think about it: Rusty was the hardest-hit of the whole group, and Trevor was his roommate. The action centered on that group of friends but never seemed to touch Trevor. NOTE: This is as much a fanmade theory as anything anyone else could come up with so don't take this as canon.