This is a multi-center, prospective registry study of subjects undergoing hemodialysis for
treatment of end-stage renal disease in a DaVita center.

The objective of this study is to understand whether and to what degree anti-SARS-CoV-2
antibodies mitigate the risk of subsequent SARS-CoV-2 infection and COVID disease within the
ESKD population.

Following informed consent, participants will undergo baseline serologic characterization for
anti-SARS-CoV-2 IgM and IgG. The study is planned to align with the present wave of COVID-19.
Enrollment will continue until the total sample size of 2500 is reached or until the study
sponsor determines. Should there be a subsequent wave of COVID- 19, participants will be
actively surveiled for evidence of SARS-CoV-2 infection and for COVID-19 disease. The
relationship between baseline serologic status and subsequent infection/disease will be
determined.

This study will have 2 distinct phases.

Phase 1 (baseline characterization) start will be triggered by the sponsor and may start at
different times at the active sites. Participants will be consented and enrolled and blood
will be collected for anti-SARS-CoV-2 antibodies.

Phase 2: Start will be triggered by the sponsor in the fall of 2020 and each geographic study
location may be triggered to start at separate times. Study participants will be followed
prospectively for incidence and severity of COVID-19. Study visits will commence upon sponsor
trigger and will occur once monthly for 4 months.