BCG Vaccination Effect on Latent Reservoir Size in Treated HIV-1 Infection:

Inclusion Criteria: * Informed consent as documented by signature (see Informed Consent Form), * Age ≥18 years, * HIV-1 infection under continuous antiretroviral therapy for ≥1.5 years as requested in the Systems X Cohort, * Current participation in the Swiss HIV Cohort Study and past participation in the Systems X Cohort. Exclusion Criteria: * History of virological failure or treatment interruption at any time, defined as HIV-1 viral load \>200c/ml at two consecutive measurements at least 4 weeks apart, * CD4 T-cell count \<200/μl at any time or \<350/μl during the past 1 year * Presence of other relevant immunosuppression according to the investigator in addition to HIV (a daily steroid intake of ≥20mg is considered clinically relevant), * History of or current clinical evidence of active tuberculosis, * Previous positive tuberculin skin test or tuberculosis INF-gamma release assay (Quantiferon-Test) within the past 10 years, * Previous BCG-vaccination within the past 10 years, * Known allergy to BCG vaccine or any of its components, * Documented current febrile illness at screening or in the past 7 days. * Women who are pregnant or breast-feeding