IVIG is IVIG
IVIG is IVIG, … the way they differ is in the additives to them (maltose, sucrose, etc.). The additives are what can cause different side effects and the toleration of one brand over another.
But if you are receiving IVIG for the treatment of CIDP, that portion doesn’t matter, according to my Dr -who is on the Foundation Board.
edit: If you are diabetic or have renal problems that will determine which brand of IVIG is best suited for your condition.