* has any bcg vaccine contraindication, known allergy to the bcg vaccine or sae to prior bcg vaccination. * history of tuberculosis * people with acquired or innate immunodeficiency. * people have already been infected with sars cov-2 (virological documentation or tdm or seropositive if serology available). * people who could not commit to follow-up for 6 months. * people not in good general condition, as assessed by the investigator. * people included in other clinical trials assessing treatment. * pregnant or breastfeeding or positive urine pregnancy at enrolment visit. * bcg vaccine given within the last year. * another live vaccine administered in the month prior to randomization. * history of anaphylaxis following vaccination. * receiving medical treatment that affects the immune response or other immunosuppressive therapy in the last year. these therapies include systemic corticosteroids (more than or equal to 10 mg for more than or equal to 2 weeks), immunosuppressant, biological agents (such as monoclonal antibodies against tumour necrosis factor (tnf)-alpha). * another vaccine administered in the month prior to inclusion and randomization. * fever \> 38°c within the past 24 hours * people with malignancies (e.g. lymphoma, leukemia, hodgkin's disease or other tumors of the reticuloendothelial system) or infected with hiv * receipt of immune globulins, blood or blood-derived products in the past 3 months * acute severe febrile illness * generalized infected skin conditions * people under legal protection measure (tutorship, curatorship or safeguard measures)

* has any bcg vaccine contraindication, known allergy to the bcg vaccine or sae to prior bcg vaccination. * history of tuberculosis * people with acquired or innate immunodeficiency. * people have already been infected with sars cov-2 (virological documentation or tdm or seropositive if serology available). * people who could not commit to follow-up for 6 months. * people not in good general condition, as assessed by the investigator. * people included in other clinical trials assessing treatment. * pregnant or breastfeeding or positive urine pregnancy at enrolment visit. * bcg vaccine given within the last year. * another live vaccine administered in the month prior to randomization. * history of anaphylaxis following vaccination. * receiving medical treatment that affects the immune response or other immunosuppressive therapy in the last year. these therapies include systemic corticosteroids (more than or equal to 10 mg for more than or equal to 2 weeks), immunosuppressant, biological agents (such as monoclonal antibodies against tumour necrosis factor (tnf)-alpha). * another vaccine administered in the month prior to inclusion and randomization. * fever \> 38°c within the past 24 hours * people with malignancies (e.g. lymphoma, leukemia, hodgkin's disease or other tumors of the reticuloendothelial system) or infected with hiv * receipt of immune globulins, blood or blood-derived products in the past 3 months * acute severe febrile illness * generalized infected skin conditions * people under legal protection measure (tutorship, curatorship or safeguard measures)

- has any bcg vaccine contraindication, known allergy to the bcg vaccine or sae to prior bcg vaccination. - history of tuberculosis - people with acquired or innate immunodeficiency. - people have already been infected with sars cov-2 (virological documentation or tdm or seropositive if serology available). - people who could not commit to follow-up for 6 months. - people not in good general condition, as assessed by the investigator. - people included in other clinical trials assessing treatment. - pregnant or breastfeeding or positive urine pregnancy at enrolment visit. - bcg vaccine given within the last year. - another live vaccine administered in the month prior to randomization. - history of anaphylaxis following vaccination. - receiving medical treatment that affects the immune response or other immunosuppressive therapy in the last year. these therapies include systemic corticosteroids (more than or equal to 10 mg for more than or equal to 2 weeks), immunosuppressant, biological agents (such as monoclonal antibodies against tumour necrosis factor (tnf)-alpha). - another vaccine administered in the month prior to inclusion and randomization. - fever > 38°c within the past 24 hours - people with malignancies (e.g. lymphoma, leukemia, hodgkin's disease or other tumors of the reticuloendothelial system) or infected with hiv - receipt of immune globulins, blood or blood-derived products in the past 3 months - acute severe febrile illness - generalized infected skin conditions - people under legal protection measure (tutorship, curatorship or safeguard measures)

- has any bcg vaccine contraindication, known allergy to the bcg vaccine or sae to prior bcg vaccination. - history of tuberculosis - people with acquired or innate immunodeficiency. - people have already been infected with sars cov-2 (virological documentation or tdm or seropositive if serology available). - people who could not commit to follow-up for 6 months. - people not in good general condition, as assessed by the investigator. - people included in other clinical trials assessing treatment. - pregnant or breastfeeding or positive urine pregnancy at enrolment visit. - bcg vaccine given within the last year. - another live vaccine administered in the month prior to randomization. - history of anaphylaxis following vaccination. - receiving medical treatment that affects the immune response or other immunosuppressive therapy in the last year. these therapies include systemic corticosteroids (more than or equal to 10 mg for more than or equal to 2 weeks), immunosuppressant, biological agents (such as monoclonal antibodies against tumour necrosis factor (tnf)-alpha). - another vaccine administered in the month prior to inclusion and randomization. - fever > 38°c within the past 24 hours - people with malignancies (e.g. lymphoma, leukemia, hodgkin's disease or other tumors of the reticuloendothelial system) or infected with hiv - receipt of immune globulins, blood or blood-derived products in the past 3 months - acute severe febrile illness - generalized infected skin conditions - people under legal protection measure (tutorship, curatorship or safeguard measures)