On Apr. 27, 2020, TGen, an affiliate of City of Hope is looking for volunteers: individuals who have run the course of COVID-19, and whose immune system may have built up antibodies against this still mysterious disease. Participants in The COVID Immunity Study must be U.S. residents, age 18 or older, have tested positive for COVID-19, and then recovered. This is a research study, and will not be used to diagnose disease among the participants.