Vaccination of animals against Mycobacterium bovis

Vaccination could potentially be used as a practical means of controlling b ovine tuberculosis in countries in which a wildlife reservoir of the diseas e is present, and also in those countries which cannot afford conventional control strategies. An understanding of the processes involved in the prote ctive immune response to tuberculosis is desirable for the rational develop ment and testing of new vaccines for tuberculosis. The authors review curre nt knowledge regarding the processes involved in protective immune response s to tuberculosis, much of which has been derived from studies in mice. Thi s knowledge is discussed in relation to the problem of using vaccination to induce protective immunity in cattle, deer and wildlife. Challenge models have now been developed to test candidate vaccines in many domestic animals and wildlife species and these models are being used to evaluate tuberculo sis vaccines. Most studies of the efficacy of tuberculosis vaccines in targ et animals have focused on the use of bacillus Calmette-Guerin (BCG), an at tenuated strain of Mycobacterium bovis. Recent advances in immunology and t he molecular biology of mycobacteria have greatly increased the options for candidate vaccines and future studies will test new types of vaccines incl uding new attenuated strains of M. bovis, sub-unit protein vaccines and rec ombinant deoxyribonucleic acid vaccines. Several of these vaccines have sho wn promising results when tested in small animal models. Although progress has been made in the development of vaccine delivery systems for animals, t he technical problems associated with vaccination of wildlife remain a chal lenge.