Do we obtain a good immune response in calves when they are vaccinated when 1-month old?
The standard recommendation, when vaccinating young calves with a tetravalent virical vaccine (e.g., against BVD, IBR, BRSV, PI-3), is to do the primary vaccination when they are 4 to 6 weeks old and a booster dose 3 or 4 weeks later. The motive for this recommendation is, on the one hand, to prevent the colostral antibodies, which are passively transferred to the calf after birth, from inactivating the vaccinal virus and compromising the response that the immune system must develop after vaccination and revaccination. On the other hand, it is also recommendable for heading off the period of greatest incidence of respiratory processes in young calves that usually increase as of this age. Two important concepts must be kept in mind; one is the duration of the colostral antibodies and the other is the duration of colostral protection. Colostral antibodies can usually be detected up to 5 or 6 months of age, but the average life of these antibodies is only 4 to 5 weeks. This means the colo
