Inclusion Criteria:  Clients of a long-term care facility 55-85 years old  Exclusion Criteria:  Known previous or current active TB disease Exposure to individual with documented active TB within previous three months Fever (>37.5 C) within the past 24 hours  Current serious underlying medical conditions:  HIV+ Currently taking immunosuppressive or immunomodulatory drugs Expect to receive chemotherapy or radiation therapy in the coming six months, receipt of chemotherapy in the past six months or undergoing chemotherapy Currently on any anti-cytokine therapy History of organ or bone marrow transplantation Individual or family history of familial or acquired immune disorder, including auto-immune disorders Neutropenia/leukopenia (<500 neutrophils/mm3 or <400 lymphocytes/mm3) Chronic kidney disease (Glomerular Filtration Rate< 30 ml/min/1.73m2) Elevated liver enzymes (alanine aminotransferase >260 IU/L or aspartate aminotransferase >200 IU/L) or Model for End-Stage Liver Disease (MELD) score ≥30 Treatment with oral or intravenous steroids at the time of screening, defined as daily doses of 10mg prednisone or equivalent for longer than 3 months. Solid or hematologic malignancy including lymphoma, leukemia and other reticuloendothelial system carcinomas within the past two years. Presence of Parkinson's disease Evidence of dermatitis at site of vaccination Living with someone with HIV, immunocompromised, taking immunosuppressive drugs Suspicion of active viral or bacterial infection, or taking antivirals or antibiotics  Any vaccine administration two weeks before or after BCG administration. For those who have received the Covid-19 vaccine, the two weeks are considered after the 2nd dose.  Doctors in Taiwan do not always encourage the use of Covid-19 vaccination due to low incidence of disease and the risk of death due to blood clots in the only approved vaccine for use (AstraZeneca). Known allergy to components of the BCG vaccine or prior serious reaction to previous BCG administration Plan to leave the long-term care facility within the next three months Taking part in any ongoing trial that includes administration of an investigational product relevant to respiratory disease Participants with cognitive impairment whose legal guardians cannot be contacted