We used to use titanium 5 on the calves. It never failed that 2 weeks after we vaccinated, they would start getting sick. I don't mean maybe he's sick maybe he's not. I mean fine today half dead tomorrow sick. We moved away from titanium and went to bovishield gold. We still get sick calves after vaccination but not near as many and nowhere near as severe. My vet and I have gone round and round arguing about this, and he swears the vaccine isn't causing it. Funny thing is, I did a test, and the calves that I only gave blackleg to didn't get sick. Only the ones that got the modified live vaccine got sick. Now I only use the modified live on the cows. Calves get cattle master with the killed virus.
TLDR: I'm not an advocate of modified live vaccines for baby calves.