As much as I don't like to (respectfully) disagree with the owner of this forum,
I wouldn't have been as optimistic if I were those doctors.
Not for his long-term prognosis but his ability to return to school so soon. Summer camp, maybe?
My sense with ATG is that you may not see a lot of symptoms on paper, but you still feel really blahhhh for a while.
According to my doctors, I tolerated the treatment "well." Easy for them to say, they didn't watch me do a face plant into my Chicken Marsala because I barely had the strength to sit up straight at the table. After about 4 months, I was hiking up mountains in full remission.
But again, the teenager factor could help him bounce back.
I guess my point is, don't get down if he has a bit of a rough time with it.