Perhaps I am only thinking about this because I work with computers, but if a spellcaster were to use an infected scroll to learn the spell contained on the scroll, does the Vanishing infection enter the caster's spell in their spellbook. So that any time they prepare that spell they risk contracting the Vanishing?
Is this too punitive? Should I just have them save with the use of the scroll and that is it or is the whole spell tainted and using it to learn from just transfers the Vanishing to the user's spell in their spellbook?
I am looking for thoughts from others who handled this in their campaigns.
The way the Vanishing works is it is the magic item itself that is infected. I don't have my HC next to me, but I believe that the only things affected were true magic items.
The spellbook is NOT a scroll or other type of magic item other than spell storage, thus not a magic item in the realms of what causes the vanishing to be spread, at least to my opinion, having run Jzadirune four times at this point.