Around the same time, he went to a music festival, ate mushrooms, and had “one of the most intense trips” of his life. Within days, he started noticing strange things.
This part is where Ted starts noticing some strange things after days of having consumed mushrooms, which is the beginning of his conspiracy theories and alteration of reality.
He mentioned that he’d recently tried to contract the disease while on a construction site by licking the steering wheels of his coworkers. When no symptoms showed, he cataloged the event as further evidence of the chip, of the vaccine. Or that the virus was a hoax
At this point, one can further understand the extent to which Ted was lost in his conspiracy theories and how it was affecting his relationship with his sister.
It seemed at once that only the machines were alive, possessed of some secret will that wouldn’t let them give up on this particular dead man.
This sentence makes one imagine and realize how John felt about the vegetative condition in which his brother was, a corpse forced to live by the machines connected to his body.