@khali Here is a good page that describes IVig
https://www.uptodate.com/contents/intravenous-immune-globulin-ivig-beyond-the-basics

It is immuno globulins (antibodies collected from 10-12K people's blood that are given IV over a period of hours for different medical conditions (usually immuno -suppressed/compromised people or for auto immune diseases). For auto immune diseases having all the new antibodies often will trick the immune system into not attacking the body organ/tissue marked for destruction.

Intravenous gamma globulin.