inclusion criteria: * documentation of laboratory-confirmed active sars-cov-2 infection, as determined by a nucleic acid (for example, reverse-transcriptase pcr) or antigen test from any respiratory tract specimen (for example, oropharyngeal, np or nasal swab, or saliva) collected ≤72 hours (3 days) prior to randomization. * participants are expected to begin study intervention ≤3 days from self-reported date of onset of any of the covid-19-related symptoms from the following list: * cough * shortness of breath or difficulty breathing * feeling feverish * chills * fatigue * body pain or muscle pain or aches * diarrhea * nausea * vomiting * headache * sore throat * nasal obstruction or congestion * nasal discharge * loss of taste * loss of smell * one or more of the following signs/symptoms present within 24 hours prior to randomization: * cough * shortness of breath or difficulty breathing * feeling feverish * chills * fatigue * body pain or muscle pain or aches * diarrhea * nausea * vomiting * headache * sore throat * nasal obstruction or congestion * nasal discharge * participants at higher risk of progression to severe covid-19 are defined as follows: * age ≥65 years * age ≥18 with 1 of the following: * obesity (body mass index \[bmi\] ≥30 kilograms per square meter \[kg/m\^2\]). note: bmi is rounded to the nearest whole number, for example 29.5 kg/m\^2 is rounded to 30 kg/m\^2. * diabetes mellitus * hypertension requiring daily prescribed therapy * cardiovascular disease (requiring daily prescribed therapy or congenital heart disease) * chronic lung disease (for example, chronic obstructive pulmonary disease, moderate to severe asthma, interstitial lung disease, cystic fibrosis, pulmonary hypertension) requiring daily prescribed therapy * chronic kidney disease, defined as known current kidney impairment with a creatinine clearance (crcl) or estimated glomerular filtration rate (egfr) \<60 milliliters (ml)/minute (min)/1.73 square meter (m\^2) within the past 12 months prior to randomization, as long as the participant does not have known crcl \<30 ml/min by cockcroft-gault or require dialysis * down syndrome * sickle cell disease * one of the following immunocompromising conditions or immunosuppressive treatments: * receiving chemotherapy or other therapies for cancer * hematologic malignancy (active or in remission) * history of a hematopoietic stem cell or a solid organ transplant * human immunodeficiency virus infection: not on antiretroviral therapy or with cluster of differentiation 4+ cell count \<200 cells per cubic millimeter * combined primary immunodeficiency disorder * taking immunosuppressive medications (for example, drugs to suppress rejection of transplanted organs or to treat rheumatologic and gastrointestinal conditions, such as anti-tumor necrosis factor agents, mycophenolate, and rituximab). note: current use of some corticosteroids is exclusionary, due to concern for possible drug-drug interaction (ddi) with s-217622.

inclusion criteria: * documentation of laboratory-confirmed active sars-cov-2 infection, as determined by a nucleic acid (for example, reverse-transcriptase pcr) or antigen test from any respiratory tract specimen (for example, oropharyngeal, np or nasal swab, or saliva) collected ≤72 hours (3 days) prior to randomization. * participants are expected to begin study intervention ≤3 days from self-reported date of onset of any of the covid-19-related symptoms from the following list: * cough * shortness of breath or difficulty breathing * feeling feverish * chills * fatigue * body pain or muscle pain or aches * diarrhea * nausea * vomiting * headache * sore throat * nasal obstruction or congestion * nasal discharge * loss of taste * loss of smell * one or more of the following signs/symptoms present within 24 hours prior to randomization: * cough * shortness of breath or difficulty breathing * feeling feverish * chills * fatigue * body pain or muscle pain or aches * diarrhea * nausea * vomiting * headache * sore throat * nasal obstruction or congestion * nasal discharge * participants at higher risk of progression to severe covid-19 are defined as follows: * age ≥65 years * age ≥18 with 1 of the following: * obesity (body mass index \[bmi\] ≥30 kilograms per square meter \[kg/m\^2\]). note: bmi is rounded to the nearest whole number, for example 29.5 kg/m\^2 is rounded to 30 kg/m\^2. * diabetes mellitus * hypertension requiring daily prescribed therapy * cardiovascular disease (requiring daily prescribed therapy or congenital heart disease) * chronic lung disease (for example, chronic obstructive pulmonary disease, moderate to severe asthma, interstitial lung disease, cystic fibrosis, pulmonary hypertension) requiring daily prescribed therapy * chronic kidney disease, defined as known current kidney impairment with a creatinine clearance (crcl) or estimated glomerular filtration rate (egfr) \<60 milliliters (ml)/minute (min)/1.73 square meter (m\^2) within the past 12 months prior to randomization, as long as the participant does not have known crcl \<30 ml/min by cockcroft-gault or require dialysis * down syndrome * sickle cell disease * one of the following immunocompromising conditions or immunosuppressive treatments: * receiving chemotherapy or other therapies for cancer * hematologic malignancy (active or in remission) * history of a hematopoietic stem cell or a solid organ transplant * human immunodeficiency virus infection: not on antiretroviral therapy or with cluster of differentiation 4+ cell count \<200 cells per cubic millimeter * combined primary immunodeficiency disorder * taking immunosuppressive medications (for example, drugs to suppress rejection of transplanted organs or to treat rheumatologic and gastrointestinal conditions, such as anti-tumor necrosis factor agents, mycophenolate, and rituximab). note: current use of some corticosteroids is exclusionary, due to concern for possible drug-drug interaction (ddi) with s-217622.

inclusion criteria: documentation of laboratory-confirmed active sars-cov-2 infection, as determined by a nucleic acid (for example, reverse-transcriptase pcr) or antigen test from any respiratory tract specimen (for example, oropharyngeal, np or nasal swab, or saliva) collected ≤72 hours (3 days) prior to randomization. participants are expected to begin study intervention ≤3 days from self-reported date of onset of any of the covid-19-related symptoms from the following list: cough shortness of breath or difficulty breathing feeling feverish chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge loss of taste loss of smell one or more of the following signs/symptoms present within 24 hours prior to randomization: cough shortness of breath or difficulty breathing feeling feverish chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge participants at higher risk of progression to severe covid-19 are defined as follows: age ≥65 years age ≥18 with 1 of the following: obesity (body mass index [bmi] ≥30 kilograms per square meter [kg/m^2]). note: bmi is rounded to the nearest whole number, for example 29.5 kg/m^2 is rounded to 30 kg/m^2. diabetes mellitus hypertension requiring daily prescribed therapy cardiovascular disease (requiring daily prescribed therapy or congenital heart disease) chronic lung disease (for example, chronic obstructive pulmonary disease, moderate to severe asthma, interstitial lung disease, cystic fibrosis, pulmonary hypertension) requiring daily prescribed therapy chronic kidney disease, defined as known current kidney impairment with a creatinine clearance (crcl) or estimated glomerular filtration rate (egfr) <60 milliliters (ml)/minute (min)/1.73 square meter (m^2) within the past 12 months prior to randomization, as long as the participant does not have known crcl <30 ml/min by cockcroft-gault or require dialysis down syndrome sickle cell disease one of the following immunocompromising conditions or immunosuppressive treatments: receiving chemotherapy or other therapies for cancer hematologic malignancy (active or in remission) history of a hematopoietic stem cell or a solid organ transplant human immunodeficiency virus infection: not on antiretroviral therapy or with cluster of differentiation 4+ cell count <200 cells per cubic millimeter combined primary immunodeficiency disorder taking immunosuppressive medications (for example, drugs to suppress rejection of transplanted organs or to treat rheumatologic and gastrointestinal conditions, such as anti-tumor necrosis factor agents, mycophenolate, and rituximab). note: current use of some corticosteroids is exclusionary, due to concern for possible drug-drug interaction (ddi) with s-217622.

inclusion criteria: documentation of laboratory-confirmed active sars-cov-2 infection, as determined by a nucleic acid (for example, reverse-transcriptase pcr) or antigen test from any respiratory tract specimen (for example, oropharyngeal, np or nasal swab, or saliva) collected ≤72 hours (3 days) prior to randomization. participants are expected to begin study intervention ≤3 days from self-reported date of onset of any of the covid-19-related symptoms from the following list: cough shortness of breath or difficulty breathing feeling feverish chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge loss of taste loss of smell one or more of the following signs/symptoms present within 24 hours prior to randomization: cough shortness of breath or difficulty breathing feeling feverish chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge participants at higher risk of progression to severe covid-19 are defined as follows: age ≥65 years age ≥18 with 1 of the following: obesity (body mass index [bmi] ≥30 kilograms per square meter [kg/m^2]). note: bmi is rounded to the nearest whole number, for example 29.5 kg/m^2 is rounded to 30 kg/m^2. diabetes mellitus hypertension requiring daily prescribed therapy cardiovascular disease (requiring daily prescribed therapy or congenital heart disease) chronic lung disease (for example, chronic obstructive pulmonary disease, moderate to severe asthma, interstitial lung disease, cystic fibrosis, pulmonary hypertension) requiring daily prescribed therapy chronic kidney disease, defined as known current kidney impairment with a creatinine clearance (crcl) or estimated glomerular filtration rate (egfr) <60 milliliters (ml)/minute (min)/1.73 square meter (m^2) within the past 12 months prior to randomization, as long as the participant does not have known crcl <30 ml/min by cockcroft-gault or require dialysis down syndrome sickle cell disease one of the following immunocompromising conditions or immunosuppressive treatments: receiving chemotherapy or other therapies for cancer hematologic malignancy (active or in remission) history of a hematopoietic stem cell or a solid organ transplant human immunodeficiency virus infection: not on antiretroviral therapy or with cluster of differentiation 4+ cell count <200 cells per cubic millimeter combined primary immunodeficiency disorder taking immunosuppressive medications (for example, drugs to suppress rejection of transplanted organs or to treat rheumatologic and gastrointestinal conditions, such as anti-tumor necrosis factor agents, mycophenolate, and rituximab). note: current use of some corticosteroids is exclusionary, due to concern for possible drug-drug interaction (ddi) with s-217622.

inclusion criteria: documentation of laboratory-confirmed active sars-cov-2 infection, as determined by a nucleic acid (for example, reverse-transcriptase pcr) or antigen test from any respiratory tract specimen (for example, oropharyngeal, np or nasal swab, or saliva) collected ≤120 hours (5 days) prior to randomization. participants are expected to begin study intervention ≤5 days from self-reported date of onset of any of the covid-19-related symptoms from the following list: cough shortness of breath or difficulty breathing feeling feverish chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge loss of taste or smell one or more of the following signs/symptoms present within 24 hours prior to randomization: cough shortness of breath or difficulty breathing feeling feverish chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge participants at high risk are defined as having 1 or more factors that lead to a higher risk of progression to severe covid-19: age ≥65 years age ≥18 with 1 of the following: obesity (body mass index [bmi] ≥30 kilograms per square meter [kg/m^2]). note: bmi is rounded to the nearest whole number, for example 29.5 kg/m^2 is rounded to 30 kg/m^2. diabetes mellitus hypertension cardiovascular disease (including congenital heart disease) chronic lung disease (for example, chronic obstructive pulmonary disease, moderate to severe asthma, interstitial lung disease, cystic fibrosis, pulmonary hypertension) chronic kidney disease, as long as the participant does not have known creatinine clearance (crcl) <30 milliliters per minute (ml/min) by cockcroft-gault or require dialysis down syndrome sickle cell disease one of the following immunocompromising conditions or immunosuppressive treatments: receiving chemotherapy or other therapies for cancer hematologic malignancy (active or in remission) history of a hematopoietic stem cell or a solid organ transplant human immunodeficiency virus infection: not on antiretroviral therapy or with cluster of differentiation 4+ cell count <200 cells per cubic millimeter combined primary immunodeficiency disorder taking immunosuppressive medications (for example, drugs to suppress rejection of transplanted organs or to treat rheumatologic and gastrointestinal conditions, such as anti-tumor necrosis factor agents, mycophenolate, and rituximab). note: current use of some corticosteroids is exclusionary, due to concern for possible drug-drug interaction (ddi) with s-217622.

inclusion criteria: documentation of laboratory-confirmed active sars-cov-2 infection, as determined by a nucleic acid (for example, reverse-transcriptase pcr) or antigen test from any respiratory tract specimen (for example, oropharyngeal, np or nasal swab, or saliva) collected ≤120 hours (5 days) prior to randomization. participants are expected to begin study intervention ≤5 days from self-reported date of onset of any of the covid-19-related symptoms from the following list: cough shortness of breath or difficulty breathing feeling feverish chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge loss of taste or smell one or more of the following signs/symptoms present within 24 hours prior to randomization: cough shortness of breath or difficulty breathing feeling feverish chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge participants at high risk are defined as having 1 or more factors that lead to a higher risk of progression to severe covid-19: age ≥65 years age ≥18 with 1 of the following: obesity (body mass index [bmi] ≥30 kilograms per square meter [kg/m^2]). note: bmi is rounded to the nearest whole number, for example 29.5 kg/m^2 is rounded to 30 kg/m^2. diabetes mellitus hypertension cardiovascular disease (including congenital heart disease) chronic lung disease (for example, chronic obstructive pulmonary disease, moderate to severe asthma, interstitial lung disease, cystic fibrosis, pulmonary hypertension) chronic kidney disease, as long as the participant does not have known creatinine clearance (crcl) <30 milliliters per minute (ml/min) by cockcroft-gault or require dialysis down syndrome sickle cell disease one of the following immunocompromising conditions or immunosuppressive treatments: receiving chemotherapy or other therapies for cancer hematologic malignancy (active or in remission) history of a hematopoietic stem cell or a solid organ transplant human immunodeficiency virus infection: not on antiretroviral therapy or with cluster of differentiation 4+ cell count <200 cells per cubic millimeter combined primary immunodeficiency disorder taking immunosuppressive medications (for example, drugs to suppress rejection of transplanted organs or to treat rheumatologic and gastrointestinal conditions, such as anti-tumor necrosis factor agents, mycophenolate, and rituximab). note: current use of some corticosteroids is exclusionary, due to concern for possible drug-drug interaction (ddi) with s-217622.

inclusion criteria: any of the following factors that lead to a higher risk of progression to severe covid-19 individuals not fully vaccinated (see note below for definition) must have one or more of the following: age ≥65 years age ≥18 with one of the following: obesity (body mass index [bmi] ≥30 kilograms per square meter [kg/m2]). note: bmi is rounded to the nearest whole number, for example 29.5 is rounded to 30 kg/m2 diabetes mellitus cardiovascular disease (including congenital heart disease) or hypertension (with at least one medication recommended or prescribed) chronic lung disease requiring daily therapy (for example, chronic obstructive pulmonary disease [copd], moderate-to-severe asthma, interstitial lung disease, cystic fibrosis, pulmonary hypertension) note: fully vaccinated is defined as having received all doses to complete the initial vaccine series for covid-19 with a vaccine that has received who eul, fda eua, or full approval (one or two doses depending on the vaccine). further, people who completed their initial covid-19 vaccination course will be considered as fully vaccinated, even if they are eligible for a third vaccine dose or booster vaccination and have not received it. individuals who are eligible regardless of vaccination status must have one or more of the following: age ≥80 years age ≥18 with one of the following: down syndrome, sickle cell disease, dementia, parkinson's disease, or care home residents one of the following immunocompromising conditions or immunosuppressive treatment: receiving chemotherapy or other therapies for cancer hematologic malignancy (active or in remission) being within 2 years from receiving a hematopoietic stem cell or at any time following a solid organ transplant hiv infection untreated or with cd4+ t lymphocyte count <200 cells per cubic millimeter (mm^3) within the past 6 months combined primary immunodeficiency disorder taking immunosuppressive medications (for example, drugs to suppress rejection of transplanted organs or to treat rheumatologic and gastrointestinal conditions such as anti-tnf agents, mycophenolate and rituximab) note: current use of some corticosteroids is exclusionary, due to concern for possible drug-drug interaction (ddi) with s-217622. documentation of laboratory-confirmed active sars-cov-2 infection, as determined by a nucleic acid (for example, pcr, reverse transcriptase-pcr) or antigen test from any respiratory tract specimen (for example, oropharyngeal, np or nasal swab, or saliva) collected ≤120 hours (5 days) prior to randomization. participants are expected to begin study intervention ≤5 days from self-reported date of onset of any of the covid-19-related symptoms from the following list: cough shortness of breath or difficulty breathing fever (measured temperature >38°c [100.4°f] or subjective fever, for example, feeling feverish) chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge loss of taste or smell one or more of the following signs/symptoms present within 24 hours prior to randomization: cough shortness of breath or difficulty breathing fever (documented temperature >38°c [100.4°f] or subjective fever, for example, feeling feverish) chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge

inclusion criteria: any of the following factors that lead to a higher risk of progression to severe covid-19 individuals not fully vaccinated (see note below for definition) must have one or more of the following: age ≥65 years age ≥18 with one of the following: obesity (body mass index [bmi] ≥30 kilograms per square meter [kg/m2]). note: bmi is rounded to the nearest whole number, for example 29.5 is rounded to 30 kg/m2 diabetes mellitus cardiovascular disease (including congenital heart disease) or hypertension (with at least one medication recommended or prescribed) chronic lung disease requiring daily therapy (for example, chronic obstructive pulmonary disease [copd], moderate-to-severe asthma, interstitial lung disease, cystic fibrosis, pulmonary hypertension) note: fully vaccinated is defined as having received all doses to complete the initial vaccine series for covid-19 with a vaccine that has received who eul, fda eua, or full approval (one or two doses depending on the vaccine). further, people who completed their initial covid-19 vaccination course will be considered as fully vaccinated, even if they are eligible for a third vaccine dose or booster vaccination and have not received it. individuals who are eligible regardless of vaccination status must have one or more of the following: age ≥80 years age ≥18 with one of the following: down syndrome, sickle cell disease, dementia, parkinson's disease, or care home residents one of the following immunocompromising conditions or immunosuppressive treatment: receiving chemotherapy or other therapies for cancer hematologic malignancy (active or in remission) being within 2 years from receiving a hematopoietic stem cell or at any time following a solid organ transplant hiv infection untreated or with cd4+ t lymphocyte count <200 cells per cubic millimeter (mm^3) within the past 6 months combined primary immunodeficiency disorder taking immunosuppressive medications (for example, drugs to suppress rejection of transplanted organs or to treat rheumatologic and gastrointestinal conditions such as anti-tnf agents, mycophenolate and rituximab) note: current use of some corticosteroids is exclusionary, due to concern for possible drug-drug interaction (ddi) with s-217622. documentation of laboratory-confirmed active sars-cov-2 infection, as determined by a nucleic acid (for example, pcr, reverse transcriptase-pcr) or antigen test from any respiratory tract specimen (for example, oropharyngeal, np or nasal swab, or saliva) collected ≤120 hours (5 days) prior to randomization. participants are expected to begin study intervention ≤5 days from self-reported date of onset of any of the covid-19-related symptoms from the following list: cough shortness of breath or difficulty breathing fever (measured temperature >38°c [100.4°f] or subjective fever, for example, feeling feverish) chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge loss of taste or smell one or more of the following signs/symptoms present within 24 hours prior to randomization: cough shortness of breath or difficulty breathing fever (documented temperature >38°c [100.4°f] or subjective fever, for example, feeling feverish) chills fatigue body pain or muscle pain or aches diarrhea nausea vomiting headache sore throat nasal obstruction or congestion nasal discharge