This is a multi-center, double-blinded study of COVID-19 infected patients randomized 1:1 to daily losartan or placebo for 10 days or treatment failure (hospital admission).

Change in PROMIS Dyspnea Scale

description: The PROMIS dyspnea scale consists of 4 subscales. 3 (1. general shortness of breath, 2. intensity, and 3. Frequency) are scored from 0 (no symptoms) to 10 (most severe). The 4th subscale is scored from 0-4 in response to the question "I've been short of breath" with 0 representing none and 4 the most severe, for a total range of 0-34. Results are difference between enrollment and day 10. There are no units.
time_frame: 10 days

Change in SF-12 Physical Composite Score

description: The SF-12 is a self-reported validated outcome measure assessing the impact of health on an individual's everyday life. Patients fill out a 12 question survey which is then scored by a clinician or researcher. Physical score is computed using the scores of twelve questions and range from 0 to 100, where a zero score indicates the lowest level of health measured by the scales and 100 indicates the highest level of health. The 33-item Severity bank assesses the severity of difficulty breathing during various specific activities (the same 33 activities assessed in Dyspnea Functional Limitations). Each activity is rated in terms of degree of dyspnea (0 = no shortness of breath, 1 = mildly short of breath, 2 = moderately short of breath, 3 = severely short of breath) while engaging in the activity over the past 7 days. Total scores range from 0 to 99 with higher scores reflecting greater levels of dyspnea during daily activity.
time_frame: 10 days

Change in SF-12 Mental Composite Score

description: The SF-12 is a self-reported validated outcome measure assessing the impact of health on an individual's everyday life. Patients fill out a 12 question survey which is then scored by a clinician or researcher. Mental composite score is computed using the scores of twelve questions and range from 0 to 100, where a zero score indicates the lowest level of health measured by the scales and 100 indicates the highest level of health.
time_frame: 10 days

Daily Maximum Temperature

description: Participants will report their maximum daily oral temperature to the study team. Outcome is reported as the mean maximum daily body temperature (in degrees Celsius) over 10 days.
time_frame: 10 days

Count of Participants With an Emergency Department or Clinic Presentation

description: Outcome is reported as the mean number of emergency department and clinic presentations combined per participant in each arm.
time_frame: 28 days

Disease Severity Rating Day 15

description: Outcome reported as the number of participants in each arm who fall into each of 7 categories. Lower scores indicate greater condition severity. The ordinal scale is an assessment of the clinical status at the first assessment of a given study day. The scale is as follows: 1) Death; 2) Hospitalized, on invasive mechanical ventilation or extracorporeal membrane oxygenation (ECMO); 3) Hospitalized, on non-invasive ventilation or high flow oxygen devices; 4) Hospitalized, requiring supplemental oxygen; 5) Hospitalized, not requiring supplemental oxygen; 6) Not hospitalized, limitation on activities; 7) Not hospitalized, no limitations on activities.
time_frame: 15 days

Change in Viral Load by Nasopharyngeal Swab at Day 9

description: Viral load is measured as number of viral genetic copies per mL.
time_frame: 9 days

Change in Viral Load by Nasopharyngeal Swab at Day 15

description: Viral load is measured as number of viral genetic copies per mL.
time_frame: 15 days

Percentage of Patients Admitted to the Intensive Care Unit Within 15 Days

description: Outcome reported as the percent of participants in each arm who require ICU admission by day 15 following randomization.
time_frame: 15 days

Need for Oxygen Therapy at 15 Days

description: Outcome reported as the percent of participants in each arm who require oxygen therapy by day 15 following randomization.
time_frame: 15 days ^[1]