Quality control and safety assessment of BCG vaccines in the post-genomic era

A hundred and five years ago, Albert Calmette and Camille Guérin began a daunting task, which is unmatched even today, that led to the most widely used vaccine in human history. Despite a century of scientific advances, BCG (an acronym for Bacillus Calmette-Guérin) remains the only vaccine for prevention of tuberculosis. Due to the fact that the use of BCG vaccines will continue, either as a stand-alone or as a prime vaccine in prime-boost immunization strategies, the World Health Organization (WHO) has underlined the necessity for further work toward better characterization, evaluation and quality control of the BCG vaccine, taking into account recent advances in genetics and molecular biology. The potential benefit of such improved characterization could be addressed to better and easier differentiation between sub-strains used by different manufacturers. It may help to ensure consistency of production in terms of genetic stability and it may also help the clinical evaluation of new antituberculosis vaccines. Last but not least, the state-of-the-art technologies could facilitate the quality control performed by the manufacturers and by National Control Authorities as well.