@elkwc LOL - I was not trying to ruffle feathers. Just stating a fact - 1 dose of killed vaccine is like paying for it and squirting it on the ground. Without the 2nd dose, you totally wasted your time and money. This is easily verified. "With
killed vaccines, the first
dose presents the antigen to the immune system, resulting in a small immune response, but little to no memory."
MLV are cheaper - but it takes better management.
I don't vaccinate my calves at weaning because they get two doses of MLV at 3 and 4 months of age (plus a nasal Inforce 3 at birth). I am able to use MLV because my cowherd is vaccinated every 12 months with MLV.