1. Aged =16 years 2. Laboratory-confirmed SARS-CoV-2 infection as determined by polymerase chain reaction (PCR), or other commercial or public health assay in any specimen < 96 h prior to randomization 3. Admitted to hospital as in-patient 4. Illness of any duration, and at least one of the following: 4.1. Radiographic infiltrates by imaging (e.g. chest x-ray, computed tomography (CT) scan) OR 4.2. Evidence of rales/crackles on physical examination OR 4.3. Peripheral capillary oxygen saturation (SpO2) =94% on room air prior to randomization OR 4.4. Requiring supplemental oxygen OR 4.5. Lymphocyte count <1 x 10(9) cells/l 5. Participant (or legally authorized representative) provides written informed consent 6. Able to take oral medication 7. Participant (or legally authorised representative) understands and agrees to comply with planned trial procedures

1. Aged =16 years 2. Laboratory-confirmed SARS-CoV-2 infection as determined by polymerase chain reaction (PCR), or other commercial or public health assay in any specimen < 96 h prior to randomization 3. Admitted to hospital as in-patient 4. Illness of any duration, and at least one of the following: 4.1. Radiographic infiltrates by imaging (e.g. chest x-ray, computed tomography (CT) scan) OR 4.2. Evidence of rales/crackles on physical examination OR 4.3. Peripheral capillary oxygen saturation (SpO2) =94% on room air prior to randomization OR 4.4. Requiring supplemental oxygen OR 4.5. Lymphocyte count <1 x 10(9) cells/l 5. Participant (or legally authorized representative) provides written informed consent 6. Able to take oral medication 7. Participant (or legally authorised representative) understands and agrees to comply with planned trial procedures