Inclusion Criteria
1. Has completed the written informed consent process.
2. Males or females, over 60 years of age as of the date of signature of the informed consent form.
3. Has a stable state of health or controlled (health parameters within the normal range for their disease) chronic diseases that do not fall within the exclusion criteria.
4. Willingness to comply with study procedures.
5. No plans to move to another city in the next 6 months and willing to be contacted by the research team within the study period.
6. Not participate in another research study in the previous 3 months, nor plans to participate in another research study in the next 6 months.
7. Agrees to avoid elective surgery during the study.
8. Willingness to receive HIV test results.
9. Not having received a BCG vaccination within the last 10 years before study vaccination.
Exlusion Criteria
1. Oral temperature ≥37.5°C, axillary ≥37.5°C or tympanic temperature ≥38.0°C in the last 24 hours.
2. Weight less than 50 kg, as well as BMI less than 18.5 or higher than 35 kg/m2.
3. History of treatment or current history of active or latent tuberculosis infection.
4. History of unprotected occupational exposure to an individual with active tuberculosis in a healthcare setting within the past 6 months.
5. Immunosuppressive drugs used within the previous 42 days (inhaled and topical corticosteroids are allowed).
6. Received documented investigational tuberculosis vaccine at any time.
7. Unstable hormonal status, i.e. subjects with any change (dose, formulation, or route) in hormone replacement therapies (including levothyroxine, insulin, estrogen, progesterone etc.) in the last 12 weeks.
8. History or laboratory evidence of any possible past, present, or future immunodeficiency status, including, but not limited to, any laboratory indication of HIV-1 infection.
9. Allergy to BCG vaccine or its components, as well as the existence of contraindications for BCG administration as described in the BCG prescribing information.
10. Previous medical history that may compromise the safety of the study participant, including but not limited to significant impairment of lung function (such as pulmonary diffusion of carbon dioxide \<80% or FEV1 ≤80%) due to tuberculosis infection or other pulmonary disease; chronic heart disease with signs of heart failure (NYHA Class II Heart Failure or more) or coronary heart disease, suspicion of progressive neurological disease; uncontrolled epilepsy, liver disease.
11. Administration of attenuated vaccines within 30 days before the start of the study or 14 days for inactivated ones.
12. Having received transfusions or blood products within the 6 months before the start of the study.
13. Uncontrolled hypertension or systolic blood pressure greater than 160 mmHg at the beginning of the study or diastolic greater than 90 mmHg.
14. Active neoplasia.
15. Stage 2 or higher chronic obstructive pulmonary disease.
16. Chronic bronchial asthma with systemic corticosteroids, or with a history of having presented crises that have led to an emergency consultation within the last 2 months.
17. Renal disease with estimated or relative creatinine clearance ≤ 70 ml/min x 1.73 m2.
18. Evidence of a new acute illness that may compromise the safety of the study participant, such as fever (oral or axillary temperature greater than or equal to 37.5°C) or suspicion of active infection.
19. History or laboratory evidence of chronic viral hepatitis.
20. History of alcohol or drug abuse in the last 2 years.
21. Smoking more than 30 cigarettes a day, or cannabis use three or more days a week.
22. History of keloid formation.
23. Congenital diseases of importance, such that they weaken the basal condition of the volunteer.
24. Congenital or acquired absence of the spleen.
25. Coagulation disorders or known thrombocytopenia of less than 100,000 platelets/mm3.
26. Having undergone chemotherapy treatment in the last 6 months.
27. Generalized urticaria in the last 2 months.
28. History of hereditary or acquired angioneurotic edema.
29. Any previous medical condition that the investigator considers may compromise the safety of the subject in the study.
30. Not being available for all study visits (both face-to-face and by telephone) and specific instructions as appropriate (fasting, abstaining from intense physical exercise during the 24 hours before the study visits and during the 72 hours after vaccination).
31. Pregnant women or women of childbearing potential (WOCBP) who are unable or unwilling to utilize appropriate methods of contraception during the study.
32. Breast-feeding women.
33. Male with heterosexual sexual activity with WOCBP who do not agree to use adequate contraception.
