The PRISM study is looking to understand what happens to children and young adults who get infected with SARS-CoV-2 and how their immune system responds. To do this, we are examining blood, urine, stool, saliva, and nasal swab samples, as well as information related to SARS-CoV-2 infection and MIS-C, collected from subjects. We will also study subjects' results on breathing tests, echocardiograms, electrocardiograms, and a chest CT scan. Participation lasts for up to 1 year and includes in-person, telephone, and video study visits.