Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/21/2004
Publication Date: 1/20/2005
Citation: Nonnecke, B.J., Waters, W.R., Foote, M.R., Palmer, M.V., Miller, B.L., Johnson, T.E., Perry, H.B., Fowler, M.A. 2005. Development of an adult-like cell-mediated immune response in calves after early vaccination with Mycobacterium bovis bacillus Calmette-Guerin. Journal of Dairy Science. 88(1):195-210. Interpretive Summary: Protection afforded the calf by early vaccination is critical given the diversity and number of potential pathogens in its environment. The present study demonstrated that early vaccination elicits an immune response in the calf that is comparable in some aspects to responses in adult cattle vaccinated in an identical fashion. This evidence of immune competency at an early age differs from the general assumption that the immune system of the young calf is developmentally immature, affecting negatively its resistance to infection. The vaccination model used in the present study may be useful in studies evaluating effects of dietary energy and protein, micronutrients or endocrines on the maturation of the immune system of the young calf. These results will be very beneficial to the dairy producers and dairy industry world-wide.
Technical Abstract: Effects of neonatal vaccination on antigen-specific cellular and humoral immune responses of dairy calves have not been well described. The purpose of this study was to characterize the ontogeny of the adaptive immune response in calves sensitized to the attenuated strain of Mycobacterium bovis, bacillus Calmette Guerin. Holstein bull calves were nonvaccinated (n=6, vaccination controls) or vaccinated subcutaneously (n=6) with bacillus Calmette-Guerin at 1 and 7 wk of age. Composition and functional capacities of blood mononuclear cell populations from calves were evaluated at 1 (pre-vaccination), 3, 6, 7, 8, 9, and 12 wk of age. Young adults (i.e. nulliparous heifers, n=4), vaccinated in an identical fashion, were sampled concurrently to evaluate effects of animal maturity on the development of the adaptive immune response. Responses of nonvaccinated calves to recall antigen (Mycobacterium bovis purified protein derivative) ex vivo and in vivo (i.e. cutaneous delayed-type hypersensitivity) were minimal or nonexistent. Responses of cells from vaccinated calves and young adults to recall antigen, however, were evident as early as wk 2 after primary vaccination. Antigen-induced T cell subset proliferation, and secretion of interferon-gamma, nitric oxide and tumor necrosis factor-alpha by cells from vaccinated calves were comparable to or greater than responses of vaccinated adults during the 11-wk study. Eleven weeks after primary vaccination, cutaneous responses of vaccinated calves and young adults to intradermal administration of antigen were pronounced and comparable, demonstrating the capacity of the bovine neonate to develop a vigorous cell-mediated immune response in vivo. Antibody responses (i.e. antibody concentrations in sera and in supernatants from antigen stimulated cultures of blood mononuclear cells) of vaccinated calves, in contrast, were markedly lower than parallel responses of vaccinated adults. In conclusion, these results suggest that the bovine neonate can mount a vigorous, adult-like cell-mediated immune response when vaccinated at an early age.