inclusion criteria * men and women * between ≥18 and ≤ 65 years old * healthcare workers (doctors, nurses and nursing assistants) from clinics and hospitals in medellín, who are directly involved in the care of patients with covid-19 * a negative test for covid-19 and being asymptomatic at baseline * are able and willing to give signed informed consent (subjects whom the investigator believes are able to understand and are willing to comply with the requirements of the protocol) exclusion criteria * have a previous diagnosis (probable or confirmed) of covid-19 * immunosuppression (pharmacological or clinical) * are taking immunosuppressive medications * pregnant or lactating women; or women of childbearing age who do not agree to take contraceptives during the month following vaccination. * have received any live or replicative vaccine one month before the time of screening. * permanent teleworking activity. * history of active tuberculosis * currently are receiving hydroxychloroquine, chloroquine, lopinavir/ritonavir, tocilizumab, or azithromycin. * known or suspected history of hypersensitivity to vaccines. * patients who do not wish to attend or who cannot keep up with the follow-up visits.

inclusion criteria * men and women * between ≥18 and ≤ 65 years old * healthcare workers (doctors, nurses and nursing assistants) from clinics and hospitals in medellín, who are directly involved in the care of patients with covid-19 * a negative test for covid-19 and being asymptomatic at baseline * are able and willing to give signed informed consent (subjects whom the investigator believes are able to understand and are willing to comply with the requirements of the protocol) exclusion criteria * have a previous diagnosis (probable or confirmed) of covid-19 * immunosuppression (pharmacological or clinical) * are taking immunosuppressive medications * pregnant or lactating women; or women of childbearing age who do not agree to take contraceptives during the month following vaccination. * have received any live or replicative vaccine one month before the time of screening. * permanent teleworking activity. * history of active tuberculosis * currently are receiving hydroxychloroquine, chloroquine, lopinavir/ritonavir, tocilizumab, or azithromycin. * known or suspected history of hypersensitivity to vaccines. * patients who do not wish to attend or who cannot keep up with the follow-up visits.

inclusion criteria - men and women - between ≥18 and ≤ 65 years old - healthcare workers (doctors, nurses and nursing assistants) from clinics and hospitals in medellín, who are directly involved in the care of patients with covid-19 - a negative test for covid-19 and being asymptomatic at baseline - are able and willing to give signed informed consent (subjects whom the investigator believes are able to understand and are willing to comply with the requirements of the protocol) exclusion criteria - have a previous diagnosis (probable or confirmed) of covid-19 - immunosuppression (pharmacological or clinical) - are taking immunosuppressive medications - pregnant or lactating women; or women of childbearing age who do not agree to take contraceptives during the month following vaccination. - have received any live or replicative vaccine one month before the time of screening. - permanent teleworking activity. - history of active tuberculosis - currently are receiving hydroxychloroquine, chloroquine, lopinavir/ritonavir, tocilizumab, or azithromycin. - known or suspected history of hypersensitivity to vaccines. - patients who do not wish to attend or who cannot keep up with the follow-up visits.

inclusion criteria - men and women - between ≥18 and ≤ 65 years old - healthcare workers (doctors, nurses and nursing assistants) from clinics and hospitals in medellín, who are directly involved in the care of patients with covid-19 - a negative test for covid-19 and being asymptomatic at baseline - are able and willing to give signed informed consent (subjects whom the investigator believes are able to understand and are willing to comply with the requirements of the protocol) exclusion criteria - have a previous diagnosis (probable or confirmed) of covid-19 - immunosuppression (pharmacological or clinical) - are taking immunosuppressive medications - pregnant or lactating women; or women of childbearing age who do not agree to take contraceptives during the month following vaccination. - have received any live or replicative vaccine one month before the time of screening. - permanent teleworking activity. - history of active tuberculosis - currently are receiving hydroxychloroquine, chloroquine, lopinavir/ritonavir, tocilizumab, or azithromycin. - known or suspected history of hypersensitivity to vaccines. - patients who do not wish to attend or who cannot keep up with the follow-up visits.