I had IVIG but it did not work probably because I could not get a full course as I had a bad reaction (aspetic menigitis). It is very unusual and I have a lot of health issues as it is so I once I started to get the headaches, they did not treat me immediately as they should have and I had a near death experience. Unless you do not have adrenals like me, doubtful you will have the same experience but do be careful if you get headaches and feel bad during the infusions.