inclusion criteria: * main study participant must be aged 12 years or older and at high risk of progression of covid-19 or \> 55 years old * sub-study participants must be aged 18 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old * participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: * main study participant must be aged 12 years or older and at high risk of progression of covid-19 or \> 55 years old * sub-study participants must be aged 18 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old * participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: main study participant must be aged 12 years or older and at high risk of progression of covid-19 or > 55 years old sub-study participants must be aged 18 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: main study participant must be aged 12 years or older and at high risk of progression of covid-19 or > 55 years old sub-study participants must be aged 18 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: main study participant must be aged 12 years or older and at high risk of progression of covid-19 or ≥ 55 years old sub-study participants must be aged 18 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: main study participant must be aged 12 years or older and at high risk of progression of covid-19 or ≥ 55 years old sub-study participants must be aged 18 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: main study participant must be aged 12 years or older and sub-study participants must be aged 18 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: main study participant must be aged 12 years or older and sub-study participants must be aged 18 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: - participant must be aged 12 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old - participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: - participant must be aged 12 years or older at time of consent and at high risk of progression of covid-19 or ≥ 55 years old - participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: - participant must be aged 12 years or older at time of consent and at high risk of progression of covid-19 or ≥ 65 years old - participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms

inclusion criteria: - participant must be aged 12 years or older at time of consent and at high risk of progression of covid-19 or ≥ 65 years old - participants must have a positive sars-cov-2 test result and oxygen saturation ≥94% on room air and have covid-19 symptoms and be less than or equal to 7 days from onset of symptoms