Also no vaccine is 100%. No one knows how the vaccines are handled,A few years ago, I bought all my CDT vaccines at a well known farm supply store. I had some Tetanus occur, as well as enterotoxemia.
I was baffled. I gave the CDT shots at all the correct intervals, etc. After checking around and lots of research and questions, asked about the practices of the store from a girl I knew that worked at the store.
What I found out was: When the trucks came in on Fri. they did not get unloaded until at least Monday. No problem, except, vaccines and penicillin need refrigerated. That was one of the hottest summers on record here.
All the vaccines I had purchased had been in that truck that 95*F weekend, and the ice packs in the coolers had warmed up. (Gel packs). (Nothing could be proven, no managers would confirm).
I guess what I am saying is, keep your vaccines refrigerated, buy from reputable places, and maybe it isn't your fault, but the handling of the medication by others that is causing your goats' illnesses.
I buy from Jeffers and PBS now.
I am fully agreeing with you there and not saying that wasn't what happened with yours but I know a lot of people look at vaccines like they will keep a animal from getting what your vaccinating against no matter what but it doesn't.