Tapering failures are very common, almost the norm. I've been on prednisone for 2.5 years and down to 3mg. Failed once getting from 4mg to 3, then failed twice trying to get to 2mg. So, I'm back at 3mg and feeling mostly ok. Looking forward to trying Kevzara if I can.

As an aside, the book An Elegant Defense is an excellent non-fiction narrative about the immune system and our current knowledge of it.