A/ Inclusion Criteria:
* For all patients:
* Age \> 18 years
* Symptomatic COVID-19 diagnosed after 01JAN2021, confirmed by RT-PCR or Antigen test
* Last SARS-CoV-2 infection diagnosed more than 12 weeks before inclusion
* Patient covered by the French health insurance
* Signature of the informed consent
* For patient with Long COVID :
* At least one of the following symptoms during the week preceding inclusion: abnormal fatigue, dyspnoea sine materia, abnormal pain (chest, joint, muscle, headache), unusual neurocognitive disorders (concentration disorders, "brain fog", language/memory disorders, paraesthesia)
* Absence of Return to Usual Health after SARS-CoV-2 infection (patient declaration)
* Absence of alternative diagnosis for the symptoms
* For COVID-19 recovered patient (Control) :
* None of the following symptoms in the 3 week before inclusion: abnormal fatigue, dyspnoea sine materia, abnormal pain (chest, joint, muscle, headache), unusual neurocognitive disorders (concentration disorders, "brain fog", language/memory disorders, paraesthesia)
* Return to Usual Health after SARS-CoV-2 infection (patient declaration)
B/ Exclusion Criteria:
* History of severe COVID-19 (Hospitalization)
* Symptoms caused by sequelae of SARS-CoV-2 infection (in particular, persistence of lung parenchymal abnormalities : pulmonary fibrosis, persistent alveolitis on CT-Scan)
* Significant Depression or anxiety symptoms, as assessed by a \> 10 score on the A or D items of the Hospital anxiety and depression scale (HAD)
* Presence of one of the following diseases:
* Inborn errors of metabolism
* estimated Glomerular filtration rate \< 30 ml/min (MDRD)
* Autoimmune disease
* Immunosuppressive treatment or immune deficiency
* Symptomatic heart failure
* Respiratory failure (COPD stage ≥ 3 or oxygen therapy)
* Solid cancer or active blood disease
* Severe malnutrition (albumin \< 30 g/L or weight loss ≥10% in 6 months)
* Obesity with BMI ≥ 35 kg/m²
* Diabetes not controlled by diet alone
* Pregnant, breastfeeding or parturient women
* Deprivation of liberty by judicial or administrative decision
* Mandatory Psychiatric Care
* Protected by decision of law
* Unable to express consent
