Additional Study Information: This study is called the COVID-19 Lung Microvascular and Parenchymal Sequelae (LUNG MaPS) Study. The purpose of the study is to learn about the effects of COVID-19 infections on the lungs and heart, and to improve our understanding of why some COVID-19 patients experience ongoing symptoms, or what is often called "long COVID." Hundreds of thousands of Americans have been infected with COVID-19. We still know relatively little about what COVID-19 might do to the lungs and heart in the long term, or why some patients have symptoms for many months after their infection. This study is designed help answer these questions. The study involves some tests of the lungs and heart, including a CT scan, a breathing test, and collection of blood and other tissue. We expect the study to take about 8 hours of your time, sometimes over two days. We also would like to stay in touch with you and might invite you back to repeat some of the tests in 2 years. We are interested in recruiting people who have had COVID-19, including people who were hospitalized as well as those who were not hospitalized for their infection. We are also recruiting people who have never had COVID-19. There can be risks associated with joining any research study. More detailed information will be provided if you are interested in learning more. There will be no direct benefit to participation in this study but we will give you results about your lungs and heart. And, the study will improve our understanding of COVID-19 and "long COVID." You will receive $300 for your time.