Effects of perinatal vaccination on humoral and cellular immune responses in cows and young calves.

OBJECTIVE

To examine the effects of perinatal vaccination on cellular and humoral responses in cows and on passive transfer of antibodies and cells to calves, and to assess the role of maternal antibodies in vaccination responses of neonatal calves.

DESIGN

Prospective randomized control trial.

ANIMALS

52 beef cows and their calves.

PROCEDURES

Assigned cows were vaccinated twice during the last month of gestation. Assigned calves were vaccinated at day 10 after birth. Antibody concentrations and cellular responses to bovine respiratory syncytial virus (BRSV) and bovine herpesvirus type 1 (BHV-1) were measured in blood and colostrum of cows and in blood of calves. Calves were assessed for passive transfer of lymphocytes.

RESULTS

At parturition, serum antibody concentrations to BRSV as well as BHV-1- and BRSV-specific blastogenic responses were significantly higher in vaccinated cows. After birth, calves from vaccinated cows had significantly higher concentrations of BRSV-specific serum antibodies, but not BHV-1 specific antibodies. Calves did not develop delayed-type hypersensitivity responses to BRSV. At weaning, lymphocytes from neonatally vaccinated calves had significantly higher values for virus-specific proliferation than did lymphocytes from unvaccinated calves; however, significant differences were not detected between groups after vaccination at weaning.

CLINICAL IMPLICATIONS

Administration of modified-live viral vaccines can boost systemic humoral and cellular responses to BRSV and BHV-1 in cows. Neonatal calves can be immunologically primed by vaccination with modified-live virus vaccines. Virus-specific memory cells persist in most calves until weaning.