BCG Vaccine Study: This study is to see if a BCG vaccine, given before travel, can help prevent tuberculosis (TB) in adults going to countries with high TB rates. The BCG vaccine from Japan is used worldwide but is experimental in the U.S., so it's being compared to a placebo, which is a fake vaccine that does nothing. About 2000 adults will join the study, and they'll be randomly chosen to get either the BCG vaccine or the placebo. The study is looking for changes in a test called the IGRA, which checks for TB infection.

• The study needs 4 to 6 visits including checkups and follow-ups.
• Participants should be 18-65 years old and in good health.
• Participants may face side effects like reactions at the shot site.

Eligibility: Participants must be in good health, not have had TB or a BCG vaccine before, and be traveling to high TB risk countries for work. They must agree to use birth control if needed and not get other vaccines during the study period.