Recent advances in the development of adenovirus- and poxvirus-vectored tuberculosis vaccines

Tuberculosis vaccine research began with the search for a vaccine that might be better than, and thus could replace, the current Bacillus Calmette Guérin (BCG) vaccine. Over the last fifteen years or so, intense research effort has led to the identification of a number of novel tuberculosis (TB) vaccines which can be divided into 4 categories: genetically modified mycobacteria, protein, plasmid DNA and viral. However, it is increasingly believed that the current BCG vaccine will continue to be used as a childhood vaccine and that more effort should be directed to developing appropriate boosting vaccines. Mounting evidence suggests that recombinant genetic vaccines, particularly recombinant viral vaccines, are effective in boosting immune activation and protection by BCG vaccination. Since modified vaccinia virus Ankara (MVA)- and adenovirus-vectored TB vaccines have been most extensively studied, this review will focus on recent advances in the development and applications of these two viral TB vaccines.