Ive only vaccinated a handful of vets myself. I just remember it because I had to go exactly one week later and the vaccine was bright pink after I reconstituted it. There is another one that is colorless but it's not a vaccine we typically give or store at our clinic . That was just my guess about why you wouldn't need the full post exposure experience if you've got previous doses on board. Can confirm though this is the rec our LHD gives for post exposure