Nasal Epithelial Genetic and Single Cell RNA COVID-19 Study

Rationale: The investigators hypothesize that genetics and the nasal epithelial response to SARS-CoV2 are critical determinants of the immune response to viral infection, and predict clinical outcome in COVID-19 patients. Objective: The main objective is to assess whether genetic background and/or the nasal epithelial gene expression in response to SARS-CoV2 is different in patients with mild, severe or very severe disease. The secondary goal of this study is to investigate a) the role of the ACE2-AngII system during SARS-CoV2 in relation to outcome b) the long-term consequences of mild, severe, and very severe COVID-19 infection c) the association between mild, severe and very severe COVID-19 with clinical \& molecular markers of disease progression d) whether the faeces microbiome, virome or metabolomics profile predicts clinical outcome in COVID-19 patients and e) to investigate whether pre-existing antibodies towards other coronaviruses play a role in severe disease development. Study design: Prospective open label clinical observational study. In this study samples will be collected from 150 COVI-19 patients ( 50 mild (group 1), 50 severe (group 2) and 50 very severe (group 3) ). Blood, nasal brushes and stool will be collected for all groups at hospital admission and 3 months after recovery, and for groups 2 \& 3 at day 3, at day 14, and before detubation Study population: A total of 150 patients diagnosed with COVID-19 will be included. The investigators aim for 50 patients per group, divided over 3 groups: Group 1 Patients with mild disease who tested positively for SARS-CoV2 infection, but only experience mild symptoms and do not need hospitalization. Group 2 Patients with severe disease admitted to hospital, without the need to be admitted to the intensive care. Group 3 Patients with very severe disease admitted to intensive care, who require mechanical ventilation. Main study parameters/endpoints: The primary endpoint of this study is the iden