I think IVIG is the pooling together of antibodies from about 20,000 people's donated blood. They wash it and sterilize it to avoid transmission of diseases by the infusion but there are still some risks.

It's used in lots of different kinds of disorders, especially autoimmune ones like Myasthenia Gravis or Guillain Barre Syndrome. They have several different theories about how it works but they think that it either gives a person missing antibodies or else knocks out some of a person's own antibodies that are attacking the person.

It's VERY expensive and it's given by IV. How often and how much depends on different doctors and different approaches.

HTH!