A growing number of young and/or otherwise healthy COVID-19 patients are progressing to symptoms serious enough to require hospital admission and intubation for breathing assistance. This project aims to better understand how and why these patients become so unwell so quickly; this information will be critical to ensuring this growing patient population gets effective care. Researchers will study a large collection of viral samples, from the BC Centre for Disease Control, collected from patients' upper and lower respiratory tract, divided into study groups based on whether patients required hospital admission and breathing assistance. Genetic information from these samples will help the researchers identify biological markers of projected disease severity and progression. Future COVID-19 patients could then be tested for these same markers so that high risk patients can be quickly identified for targeted interventions.