Inclusion Criteria:  Willing to participate in the study and provide written informed consent Male and female adults aged > 18 years and less than 65 years Must have had clinically suspected COVID-19 and a positive antibody test or a documented SARS-CoV-2 infection (a positive reverse transcription polymerase chain reaction test) at least 12 weeks prior to Screening Must have fatigue-predominant PASC Other than PASC, a subject must be in good health without other significant medical or not well controlled medical or psychiatric conditions  Exclusion Criteria:  Other than PASC, have an explanation for fatigue Other than PASC, a history or presence of an uncontrolled, clinically significant disease Medical history that includes of Non-invasive or invasive ventilatory support for COVID 19, Intensive care unit or other high dependency unit admission for COVID-19, Hospitalization for >1 week for COVID-19 without intubation