Determine how long after infection people shed COVID-19 virus, including live virus, which suggests they may still be contagious

Compare how novel variants affect the duration of viral shedding

Determine how COVID-19 treatments, such as monoclonal antibodies and nirmatrelvir-ritonavir (Paxlovid) affect shedding of the virus

Determine how the immune system affects duration of viral shedding, particularly among people with immune system disorders or those on immunosuppressive therapies

Measure if and how often the SARS-CoV-2 virus mutates among people on treatment for COVID-19 or with prolonged infection due to immune deficiencies