BCG Revaccination in Children and Adolescents

Inclusion Criteria: * Healthy household contacts aged 6 to 18 yr * Previously vaccinated with BCG at birth or least 5 years ago - evidence of scar or documented immunisation record. * General good health - through history and baseline screening * Agrees to continue in the study for 2 years post enrollment * Children previously treated for LTBI and completed treatment at least 6 months ago - can also be included. However, they should be current HHC Exclusion Criteria: * Any acute illness on recruitment day (Evaluate the child again at a later stage) * Fever ≥38 degree Celsius on recruitment day (Evaluate the child again at a later) * History of autoimmune disease * Pregnancy - female participants \> 15 years of age will have pregnancy test done after caretakers and participants informed consent * Evidence of active TB disease * On treatment for active TB disease or LTBI * HIV positive or any history or present possible immunodeficiency condition * History of allergic reactions to vaccines in past * Pre-existing liver dysfunction * ALT/AST is ≥ 3 times upper limit of normal (ULN) in the presence of symptoms or ≥ 5 times the ULN in the absence of symptoms and/or total bilirubin greater than ULN along with raised ALT/AST.