This is a prospective, longitudinal cohort study of immunosuppressed patients living in households with and without children to assess the role of household contact with children in the transmission of SARS-CoV-2 to immunocompromised patients. This study will be enrolling both pediatric and adult patients who are immunosuppressed, as well as their household members who agree to participate. Through careful collection of epidemiological data in combination with biological specimens, risk factors for SARS- CoV-2 in immunocompromised patients will be identified. During the initial study visit, informed consent will be obtained, the study questionnaire will be completed and the participant will provide biological specimens including nasal mid-turbinate swabs, saliva and blood. Thereafter, participants will complete at-home saliva collections and questionnaires on a weekly basis for 6 months. If our research-use only SARS-CoV-2 test is positive, participants will be referred immediately to University of California at Los Angeles(UCLA) Health for medical attention and will be followed every 3 days with nasal swabs and saliva samples, and weekly blood specimens and optional rectal swabs or fresh stool collection. Biological specimen and questionnaire follow-up will occur for 6 months for uninfected participants or until the of end of viral shedding and immunologic profiling for patients infected with SARS-CoV-2, whichever is longer. All participants will be followed at 6 months with the same baseline measurements and then participants will be contacted by telephone at 1 year.

The clinical data and biological specimens collected in this initial study will provide will inform and allow future studies of clinical outcomes, viral characteristics, and immune responses to SARS-CoV-2 infection.