Inclusion Criteria:

• * Age 7 to ≤21 years
• * History of SARS-CoV-2 infection, documented by positive PCR and/or antigen test
• * SARS-CoV-2 Antigenemia, defined as any detectable presence of full-length spike protein and/or Spike S1 subunit in plasma
• * Ongoing, worsening, new, or recurrent symptoms present ≥4 weeks after SARS-CoV-2 infection.Symptoms include but are not limited to fatigue, malaise, headache, cognitive impairment, neuropsychiatric symptoms, decreased exercise tolerance, post exertional malaise, dyspnea, cough, chest pain, palpitations, tachycardia, gastrointestinal symptoms, musculoskeletal symptoms, fever, lightheadedness, insomnia and other sleep disturbances, anosmia or dysgeusia, pain, paresthesia, menstrual cycle irregularities, erectile dysfunction.

Exclusion Criteria:

• * Age ≤6 years or \>22 years at time of enrollment
• * Pregnancy and/or lactation
• * Female participant of childbearing age unwilling to use an acceptable method of birth control for the duration of the study
• * Inability to tolerate drug
• * Unstable medical conditions or significant co-morbid disease that, by the investigator's determination would make the participant unsuitable for enrollment
• * Participation in any other clinical investigation using an experimental drug within 30 days prior to screening
• * Intent to participate in another clinical study while participating in this clinical trial
• * Blood/plasma donation and or blood loss greater than 400 mL within 90 days, or greater than 200 mL within 30 days prior to screening
• * Known hypersensitivity to any of the formulation components of AT1001.
• * Abnormal baseline liver function as indicated by AST or ALT ≥3 times the upper limit of normal (ULN), or direct bilirubin ≥2x ULN for age
• * Abnormal baseline renal function, defined as glomerular filtration rate ≤50 mL/min/1.73m2