Observational Study of the Association of Immunological and Inflammatory Biomarkers in COVID-19 Naïve and Infected Participants and Severity of Disease. Thirty naive and 30 COVID positive participants will have a blood sample taken after informed consent and be assessed for COVID symptoms according to WHO classification. Participants will be followed monthly for 6 months. At each contact, participants will be assessed for COVID symptoms and progress since the previous visit.

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.

Inclusion Criteria:

1. Signed informed consent (IC) within 4 days of COVID-19 test.
2. Age 18 or older
3. COVID-19 test

Group 1: negative COVID-19 test Group 2: positive COVID-19 test with Severe or Critical symptoms of disease (per WHO Guidance).

Exclusion Criteria:

1. Any autoimmune disease or immune-modulator therapy.
2. Mild or Moderate symptoms of COVID-19 disease (per WHO Guidance).

Participants at least 18 years of age who do not have autoimmune disease or are not taking immune-modulator therapy and may or may not have a positive COVID-19 test will be entered into one of two groups for Stage 1 of the study. (Stage 2 is TBD).

• 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