Last set of heptavac doses, I did inject myself, or at least, put the needle in my finger. Fortunately it was a clean needle, before I'd started doing any sheep, but it went right into the knuckle, swelled up something rotten and involved a trip to A&E plus some awkward conversations with the doctors.
I'd been umming and aahing about whether to use the guard or not. Guess I'll be using it in the future.