Due to the way a calf's immune system is... vaccinating before ~2 months of age does nothing other than make you feel good that they've been "vaccinated". That's the reason for a bangs vaccination not being given before FOUR months of age. I try to work all calves in one group at once, so it ends up that they're well over 2 months of age, healthy, not stressed, etc. Vaccinate for 8-way clostridium, 5-way BVD/IBR/PI3/BRSV, 5-way Lepto and Vibrio. And worm. And then I booster everything at the appropriate time...
can't see the point in wasting vaccinations on a calf that's too young, and can't see the point in wasting them because you never do the second "booster" that they really need.