Priming the Immune System for IBR and BVD with One Dose of Killed Vaccine

Immunization with a Follow up Dose of MLV

Abstract

A field trial was conducted in a cow/calf operation to evaluate the SN titer response to BVD and IBR virus following vaccination with either one or two doses of vaccines. Group 1 received two doses of vaccine. The first dose of vaccine was given 3 weeks prior to weaning and contained killed fractions of IBR and BVD. The second dose was given at weaning and was a four-way modified live vaccine (mlv) (IBR,BVD ,BRSV,PI3). Group 2 received only one dose of 4-way mlv vaccine at weaning. Group 3 was not vaccinated and remained with the herd as sentinels. SN titer results were compared to see if the antibody response elicited by a mlv could be primed with one dose of killed vaccine.

The results from this trial indicate that one dose of killed vaccine, administered 3 weeks prior to a dose of mlv vaccine, effectively primed the immune response. The follow up dose of mlv vaccine administered at weaning elicited a rapid and elevated antibody titer response in Group 1 calves compared to Group 2 calves; an indication that priming had taken place.

The findings in this study support a vaccination program tailored for the cow/calf operation where a priming dose of killed vaccine is given before weaning, with a follow up immunizing dose of mlv vaccine given at weaning.