Vaccination Against Tuberculosis: Past Problems and Future Hopes

Abstract

The only available vaccine against tuberculosis, Bacille Calmette-Guérin (BCG), is a living, attenuated derivative of Mycobacterium bovis. It affords protection against primary tuberculosis with an efficacy that varies from region to region from about 80% protection to no protection at all. It gives little or no protection against postprimary, often infectious, tuberculosis and thus plays a minor role in overall disease control.

A clearer understanding of immune responses in tuberculosis combined with advances in nucleic acid technology raises hopes for the development of better vaccines. Approaches currently under investigation include modified ways of administering BCG, construction of genetically engineered living vaccines, development of nonviable subunit vaccines, inoculation of naked DNA coding for protective epitopes and preparation of vaccines containing adjuvants that affect the nature of the immune response. The clinical evaluation of new vaccines will, however, pose major difficulties.

Key Words:

Bacille Calmette-Guérin - tuberculosis - vaccination