inclusion criteria: - subject (or legally authorized representative) provides informed consent (written or oral) prior to initiation of any study procedures. - male or non-pregnant, non-lactating female. women of child-bearing potential must have a confirmed negative serum pregnancy test at the time of screening and must use a highly effective contraceptive method throughout the study (such as implants, injectables, hormonal contraceptives and condom, double barrier contraception [i.e., condom + diaphragm/spermicidal gel or foam]) and until one month after completing treatment with the study medication. in the case of hormonal contraception, women should have been on a stable regimen for a minimum of three months before study enrolment. women not of child-bearing potential include post-menopausal females (defined as having a history of amenorrhea for at least one year) or a documented status as being surgically sterile (hysterectomy, bilateral oophorectomy, tubal ligation/salpingectomy). men must use an effective contraception method (i.e., condom + diaphragm/spermicidal gel or foam, or vasectomy), and should not donate semen during the study. men are considered to be fertile from the time of puberty, except for those men with permanent sterility secondary to bilateral orchiectomy. - at least 50 years of age and not older than 85 years of age at time of enrolment - confirmed sars-cov-2 infection defined as: positive real-time polymerase chain reaction (rt-pcr) result in sample collected in 96 hours prior to randomisation, or positive antigenic test result in sample collected in 96 hours prior to randomisation. - radiological confirmation of pneumonia. - at least one of the following respiratory signs or symptoms (one option): spo2 ≤ 93% at rest in ambient air, or requiring supplemental oxygen up to 5 l/min to maintain a spo2 ≥ 88%. - at least one of the following risk factors: age ≥ 60 years, medical history of chronic pulmonary disease, moderate or severe asthma, chronic obstructive pulmonary disease, emphysema, diabetes mellitus (type 1 or 2), requiring one ongoing medication or insulin for treatment, hypertension, requiring at least one ongoing medication for treatment, medical history of coronary heart disease or congestive heart failure, or body mass index (bmi) ≥ 30 kg/m2. - subject (or legally authorized representative) understands and agrees to comply with planned study procedures. - subject (or legally authorized representative) agrees to not participate in any other clinical trial, including clinical trials for the treatment or prevention of covid-19 or sars-cov-2 through day 30.

inclusion criteria: - subject (or legally authorized representative) provides informed consent (written or oral) prior to initiation of any study procedures. - male or non-pregnant, non-lactating female. women of child-bearing potential must have a confirmed negative serum pregnancy test at the time of screening and must use a highly effective contraceptive method throughout the study (such as implants, injectables, hormonal contraceptives and condom, double barrier contraception [i.e., condom + diaphragm/spermicidal gel or foam]) and until one month after completing treatment with the study medication. in the case of hormonal contraception, women should have been on a stable regimen for a minimum of three months before study enrolment. women not of child-bearing potential include post-menopausal females (defined as having a history of amenorrhea for at least one year) or a documented status as being surgically sterile (hysterectomy, bilateral oophorectomy, tubal ligation/salpingectomy). men must use an effective contraception method (i.e., condom + diaphragm/spermicidal gel or foam, or vasectomy), and should not donate semen during the study. men are considered to be fertile from the time of puberty, except for those men with permanent sterility secondary to bilateral orchiectomy. - at least 50 years of age and not older than 85 years of age at time of enrolment - confirmed sars-cov-2 infection defined as: positive real-time polymerase chain reaction (rt-pcr) result in sample collected in 96 hours prior to randomisation, or positive antigenic test result in sample collected in 96 hours prior to randomisation. - radiological confirmation of pneumonia. - at least one of the following respiratory signs or symptoms (one option): spo2 ≤ 93% at rest in ambient air, or requiring supplemental oxygen up to 5 l/min to maintain a spo2 ≥ 88%. - at least one of the following risk factors: age ≥ 60 years, medical history of chronic pulmonary disease, moderate or severe asthma, chronic obstructive pulmonary disease, emphysema, diabetes mellitus (type 1 or 2), requiring one ongoing medication or insulin for treatment, hypertension, requiring at least one ongoing medication for treatment, medical history of coronary heart disease or congestive heart failure, or body mass index (bmi) ≥ 30 kg/m2. - subject (or legally authorized representative) understands and agrees to comply with planned study procedures. - subject (or legally authorized representative) agrees to not participate in any other clinical trial, including clinical trials for the treatment or prevention of covid-19 or sars-cov-2 through day 30.

inclusion criteria: - subject (or legally authorized representative) provides informed consent (written or oral) prior to initiation of any study procedures. - male or non-pregnant, non-lactating female. women of child-bearing potential must have a confirmed negative serum pregnancy test at the time of screening and must use a highly effective contraceptive method throughout the study (such as implants, injectables, hormonal contraceptives and condom, double barrier contraception [i.e., condom + diaphragm/spermicidal gel or foam]) and until one month after completing treatment with the study medication. in the case of hormonal contraception, women should have been on a stable regimen for a minimum of three months before study enrolment. women not of child-bearing potential include post-menopausal females (defined as having a history of amenorrhea for at least one year) or a documented status as being surgically sterile (hysterectomy, bilateral oophorectomy, tubal ligation/salpingectomy). men must use an effective contraception method (i.e., condom + diaphragm/spermicidal gel or foam, or vasectomy), and should not donate semen during the study. men are considered to be fertile from the time of puberty, except for those men with permanent sterility secondary to bilateral orchiectomy. - at least 50 years of age and not older than 80 years of age at time of enrolment - confirmed sars-cov-2 infection defined as: positive real-time polymerase chain reaction (rt-pcr) result in sample collected in 96 hours prior to randomisation, or positive antigenic test result in sample collected in 96 hours prior to randomisation. - radiological confirmation of pneumonia. - at least one of the following respiratory signs or symptoms (one option): spo2 ≤ 93% at rest in ambient air, or requiring supplemental oxygen up to 5 l/min to maintain a spo2 ≥ 88%. - at least one of the following risk factors: age ≥ 60 years, medical history of chronic pulmonary disease, moderate or severe asthma, chronic obstructive pulmonary disease, emphysema, diabetes mellitus (type 1 or 2), requiring one ongoing medication or insulin for treatment, hypertension, requiring at least one ongoing medication for treatment, medical history of coronary heart disease or congestive heart failure, or body mass index (bmi) ≥ 30 kg/m2. - subject (or legally authorized representative) understands and agrees to comply with planned study procedures. - subject (or legally authorized representative) agrees to not participate in any other clinical trial, including clinical trials for the treatment or prevention of covid-19 or sars-cov-2 through day 30.

inclusion criteria: - subject (or legally authorized representative) provides informed consent (written or oral) prior to initiation of any study procedures. - male or non-pregnant, non-lactating female. women of child-bearing potential must have a confirmed negative serum pregnancy test at the time of screening and must use a highly effective contraceptive method throughout the study (such as implants, injectables, hormonal contraceptives and condom, double barrier contraception [i.e., condom + diaphragm/spermicidal gel or foam]) and until one month after completing treatment with the study medication. in the case of hormonal contraception, women should have been on a stable regimen for a minimum of three months before study enrolment. women not of child-bearing potential include post-menopausal females (defined as having a history of amenorrhea for at least one year) or a documented status as being surgically sterile (hysterectomy, bilateral oophorectomy, tubal ligation/salpingectomy). men must use an effective contraception method (i.e., condom + diaphragm/spermicidal gel or foam, or vasectomy), and should not donate semen during the study. men are considered to be fertile from the time of puberty, except for those men with permanent sterility secondary to bilateral orchiectomy. - at least 50 years of age and not older than 80 years of age at time of enrolment - confirmed sars-cov-2 infection defined as: positive real-time polymerase chain reaction (rt-pcr) result in sample collected in 96 hours prior to randomisation, or positive antigenic test result in sample collected in 96 hours prior to randomisation. - radiological confirmation of pneumonia. - at least one of the following respiratory signs or symptoms (one option): spo2 ≤ 93% at rest in ambient air, or requiring supplemental oxygen up to 5 l/min to maintain a spo2 ≥ 88%. - at least one of the following risk factors: age ≥ 60 years, medical history of chronic pulmonary disease, moderate or severe asthma, chronic obstructive pulmonary disease, emphysema, diabetes mellitus (type 1 or 2), requiring one ongoing medication or insulin for treatment, hypertension, requiring at least one ongoing medication for treatment, medical history of coronary heart disease or congestive heart failure, or body mass index (bmi) ≥ 30 kg/m2. - subject (or legally authorized representative) understands and agrees to comply with planned study procedures. - subject (or legally authorized representative) agrees to not participate in any other clinical trial, including clinical trials for the treatment or prevention of covid-19 or sars-cov-2 through day 30.