Current inclusion criteria as of 11/10/2021: 1. Aged =16 at time of consent 2. Exhibiting symptoms associated with COVID-19 3. Positive for SARS-CoV-2 on valid COVID-19 test 4. Point 2 or 3 on the WHO COVID-19 ordinal severity scale at the time of randomisation (symptomatic independent, symptomatic assistance needed) 5. Able to provide written informed consent 6. Negative pregnancy test if the participant is of childbearing potential 7. Able to swallow oral medication Previous inclusion criteria: 1. Aged =16 at time of consent 2. Exhibiting symptoms associated with COVID-19 3. Positive for SARS-CoV-2 on valid COVID-19 test 4. Point 1, 2, 3, or 4 on the WHO COVID-19 ordinal severity scale at the time of randomisation (asymptomatic with positive valid COVID19 test, symptomatic independent, symptomatic assistance needed, or hospitalized, with no oxygen therapy) 5. Have =10% risk of death should they be admitted to hospital as defined by the ISARIC4C risk index (https://isaric4c.net/risk) 6. Able to provide written informed consent 7. Negative pregnancy test if the participant is of childbearing potential 8. Able to swallow oral medication

Current inclusion criteria as of 11/10/2021: 1. Aged =16 at time of consent 2. Exhibiting symptoms associated with COVID-19 3. Positive for SARS-CoV-2 on valid COVID-19 test 4. Point 2 or 3 on the WHO COVID-19 ordinal severity scale at the time of randomisation (symptomatic independent, symptomatic assistance needed) 5. Able to provide written informed consent 6. Negative pregnancy test if the participant is of childbearing potential 7. Able to swallow oral medication Previous inclusion criteria: 1. Aged =16 at time of consent 2. Exhibiting symptoms associated with COVID-19 3. Positive for SARS-CoV-2 on valid COVID-19 test 4. Point 1, 2, 3, or 4 on the WHO COVID-19 ordinal severity scale at the time of randomisation (asymptomatic with positive valid COVID19 test, symptomatic independent, symptomatic assistance needed, or hospitalized, with no oxygen therapy) 5. Have =10% risk of death should they be admitted to hospital as defined by the ISARIC4C risk index (https://isaric4c.net/risk) 6. Able to provide written informed consent 7. Negative pregnancy test if the participant is of childbearing potential 8. Able to swallow oral medication

1. Aged =16 at time of consent 2. Exhibiting symptoms associated with COVID-19 3. Positive for SARS-CoV-2 on valid COVID-19 test 4. Point 1, 2, 3, or 4 on the WHO COVID-19 ordinal severity scale at the time of randomisation (asymptomatic with positive valid COVID19 test, symptomatic independent, symptomatic assistance needed, or hospitalized, with no oxygen therapy) 5. Have =10% risk of death should they be admitted to hospital as defined by the ISARIC4C risk index (https://isaric4c.net/risk) 6. Able to provide written informed consent 7. Negative pregnancy test if participant is of childbearing potential 8. Able to swallow oral medication

1. Aged =16 at time of consent 2. Exhibiting symptoms associated with COVID-19 3. Positive for SARS-CoV-2 on valid COVID-19 test 4. Point 1, 2, 3, or 4 on the WHO COVID-19 ordinal severity scale at the time of randomisation (asymptomatic with positive valid COVID19 test, symptomatic independent, symptomatic assistance needed, or hospitalized, with no oxygen therapy) 5. Have =10% risk of death should they be admitted to hospital as defined by the ISARIC4C risk index (https://isaric4c.net/risk) 6. Able to provide written informed consent 7. Negative pregnancy test if participant is of childbearing potential 8. Able to swallow oral medication