In case any Canadians read this, all Canadian call signs issued today are "vanity". You choose when you register for your privileges, which you will do online just a few minutes after the examiner uploads your results to Industry Canada.
2+3 callsigns (i.e. aa0aaa) are all you can have at first. After five years you can apply to change to (or have in addition) a 2+2 (i.e. aa0aa) callsign for a $60 Cdn fee. I suggest keeping your old callsign and adding the new one, unless you don't care about having a 2+2.