This is an observational study of participants who are being or have been tested for
COVID-19. Participants with or without COVID-19 will be entered into one of two groups
for Stage 1 and one of three groups for Stage 2.

Stage 1:

- Group 1: Participants whose COVID-19 test is negative and who do not have symptoms
of COVID-19 disease.

- Group 2: Participants whose COVID-19 test is positive and who have Severe or
Critical symptoms of COVID-19 disease.

Stage 2:

- Group 1: Participants whose COVID-19 test is negative and who do not have symptoms
of COVID-19 disease.

- Group 2: Participants whose COVID-19 test is positive and who have Mild or Moderate
symptoms of COVID-19 disease.

- Group 3: Participants whose COVID-19 test is positive and who have Severe or
Critical symptoms of COVID-19 disease.

During Stage 1, Group 1 participants will be matched to Group 2 subjects as follows: Age:
18-64 and >65; Race: Caucasian, Latino, African American, other; Sex: Male or Female Each
participant will be assigned a study number. The study case report form (CRF) will record
the participants initials, age and study number. Participants will have blood drawn for
biomarkers. All samples will be identified using the participants age and study number.
Blood volume will be approximately ten milliliters to yield at least four 1 ml serum
aliquots. Serum will be frozen at -80ºF and stored. Batch shipments of the serum will
occur during the study and sent to AccessDx Laboratory in Houston TX. Laboratory
procedures for AccessDx are presented in Appendices B and C. AccessDx will perform the
following biomarker tests on the serum: Interleukins 1B, 6, 8,10, 22; CRP; Ferritin;
Interferon-ꝩ; MIP 1α and 1β; TNF; VEGF A, B, C.

Participants will be followed for up to 6 months and have monthly calls from the study
staff. As much as possible, the participant will be contacted by the same study member at
each follow-up visit. If agreed with the participant, information about the participants
status may be collected on email or text. Participants will be asked specific questions
and their responses recorded on a paper CRF. At enrollment and at each follow-up call,
the participant's severity of COVID-19 disease will be categorized based on WHO Interim
guidance 27 May 2020 as follows:

- Mild cases are marked by the onset of symptoms such as fever, cough, fatigue,
shortness of breath, headache, diarrhea, and so forth, without evidence of viral
pneumonia or hypoxia.

- Moderate cases include clinical signs of pneumonia (fever, cough, dyspnea, fast
breathing) but no signs of severe pneumonia, including SpO2 ≥ 90% on room air.

- Severe cases demonstrate clinical signs of pneumonia (fever, cough, dyspnea, fast
breathing) plus one of the following: respiratory rate > 30 breaths/min; severe
respiratory distress; or SpO2 < 90% on room air.

- Critical cases present symptoms such as acute respiratory distress syndrome (ARDS),
sepsis and/or septic shock A participant's engagement in the study will be
approximately 6 months. Recruitment is expected to last 6 months. It is expected
that the total study for Stage 1 will be one year. The duration of Stage 2 will not
be determined until results from Stage 1 are available. The number of investigator
sites for Stage 1 is expected to be up to 3 and for Stage 2, up to 50.