PARIS — Around 15 vaccine candidates are being developed in the battle against tuberculosis to compensate for the poor efficacy of the Bacillus Calmette-Guérin (BCG) vaccine. Three of these candidates are in phase 3 trials. Of these candidates, one of the most promising has been shown to be 50% effective in adolescents and young adults, which is an exceptional outcome for a population that is poorly protected by the BCG vaccine.