Testing if BCG (Bacille Calmette-Guérin) Vaccination Can Induce Innate Immune Training in Adult People Above 50 Years of Age in Guinea-Bissau

Inclusion Criteria: * adults above 50 years of age Exclusion Criteria: * Participants who received BCG in the last 10 years will be excluded. * Adults who were mild to severe ill in the last 2 week will be excluded. * Adults how have been in contact with the health system (hospital or health center) for the last 14 days will be excluded. * People that show signs of overt disease will not be enrolled, but treated according to local standards and invited back when better. * If the person has any sign of TB, they will excluded and be referred to the TB clinic for further investigations and treatment. * All participants will be tested for HIV. If the test is positive, they will have an opportunity to talk with a psychologist, and we will refer them to the HIV clinic. HIV positive persons will be excluded from the present study.