The current SARS-CoV-2 pandemic presents a serious challenge to public health. Individuals infected with SARS-CoV-2 experience extremes in symptomatology ranging from a complete lack of symptoms to rapidly worsening end-stage pulmonary disease. The explanatory mechanism underlying susceptibility to severe disease remains unknown. We hypothesize that underlying genetic factors are at least partially explanatory. We aim to employ a phenotypic extremes approach to rapidly ascertain severely and mildly affected COVID-19 patients for genomic interrogation to identify germline and somatic variants that may play a role in host susceptibility to disease to correlate those phenotypic extremes with genetic variants. We will employ both a rare and common variant approach, using both genome sequencing and SNP chip analysis and B and T cell repertoire interrogation.