A randomized, double-blind, controlled Phase I study conducted at CHUV, Lausanne, Switzerland, to compare MTBVAC to licensed BCG in healthy, PPD-negative adult male and female volunteers. The study involves random allocation of up to 36 subjects (4 vaccine groups of 9 volunteers fulfilling the inclusion criteria) to MTBVAC (tested at three separate doses) or standard dose BCG (on a 3 verum : 1control basis) in a dose-escalation manner to one of three cohorts. Each cohort includes 9 subjects set to receive MTBVAC lowest dose 5x10E03, or MTBVAC intermediate dose 5x10E04, or high dose 5x10E05 colony forming units (CFU) in 0.1 mL and 3 subjects set to receive standard dose BCG (5x10E05 CFU in 0.1 mL). A single intradermal injection is given in the non-dominant arm of each volunteer starting with the lowest MTBVAC dose. Each MTBVAC vaccine dose is administered staggered by cohort, starting with the cohort with the lowest MTBVAC dose level. After at least 35 days of follow-up within each cohort a safety review and evaluation by Independent Data Safety Monitoring Board provides go/no-go for vaccination of the subsequent cohorts if no safety issues as defined by preset stopping rules.