Vaccination against M. tuberculosis – what next after BCG?

摘要

Tuberculosis (TB) still remains a huge global health problem. An increase in TB has been observed in many parts of the world, especially in poor and densely populated sub-Saharan Africa and Asia. Tuberculosis affects not only the developing countries but also the relatively wealthy regions of Europe, particularly Eastern Europe, where drug-resistant mycobacterial strains are increasingly reported.Control of tuberculosis expansion is very difficult. It requires the long-term use of anti-mycobacterial drugs. Additionally, the HIV epidemic and the phenomenon of multi-drug resistance are assumed to be responsible for the increase in TB cases. Therefore the most reasonable form of anti-TB protection seems to be effective vaccination.At the beginning of the twentieth century the BCG vaccine was introduced into general use as the first and so far the only immune protector against tuberculosis. Now it is known that this vaccine is not powerful enough and induces protection at a relatively low level. Hence ongoing research on the development of a more powerful anti-mycobacterial vaccine is still needed. Many of the new formulations are in phase II or III of clinical trials and the results are promising. The search for new vaccines involves several strategies: modified virulence-attenuated Mycobacterium tuberculosis strains, recombination of attenuated M. bovis BCG bacilli, immunogenic mycobacterial proteins and DNA encoding selected proteins as well as unrelated microorganisms used as carriers of mycobacterial antigens. The wide range of concepts is extremely important because new vaccines should serve for immunization of the broadest possible population, not only healthy individuals but also those who are immunocompromised.