The propose is to test innate immune training in a pilot study of 40 adults >50 years of age people in Guinea-Bissau. The hypothesis is that BCG vaccination will be associated with increased innate immune training measured as increased cytokine release after in vitro Peripheral Blood Mononuclear Cells (PBMC) stimulation with e.g. Mycobacterium Tuberculosis, Staphylococcus Aureus, Candida Albicans and Streptococcus Pneumoniae.