Study of How COVID-19 Affects Blood Cells and the Immune System

Official Study Title: COVID-19–associated Lymphopenia Pathogenesis Study in Blood (CALYPSO)

This study is being conducted in cooperation with MedStar Georgetown University Hospital and Washington Hospital Center in Washington, D.C. Those asked to join this study either have COVID-19 or have recently recovered. We want to learn more about how SARS-CoV-2, the virus that causes COVID-19, affects the body, specifically how it affects blood cells and the immune system.

One symptom of this disease is a reduction in the number of cells called lymphocytes in your blood. Lymphocytes are a type of white blood cell that fights infections. With fewer lymphocytes, the body cannot effectively fight back against SARS-CoV-2, the virus that causes COVID-19. We want to better understand how SARS-CoV-2 affects these blood cells. This information may give us ideas for new treatments.

What does the study involve?

If you agree to join, then we will collect some blood from you for research tests using a needle and syringe. We will also review your medical records. If you have recovered from COVID-19, then we may also ask to collect extra white blood cells with a procedure called leukapheresis, collect material from your nostril (inside of nose) and rectum using a cotton swab, and do an echocardiogram to look at your heart. Your participation in the study will end after we finish these procedures.

A total of 125 individuals are expected to participate in this study. Volunteers will be compensated.

Who can participate?

  • You are at least 18 years old

  • You currently have COVID-19 (with or without a previous COVID-19 vaccination), or you have recently recovered at least one month ago

  • You allow the NIH to store blood and tissue samples for future research

  • You are in the D.C. Metro area and able to travel to the NIH in Bethesda, Maryland

Where is it taking place?

The NIH in Bethesda, Maryland, and MedStar Georgetown University Hospital and Washington Hospital Center in Washington, D.C.

Visit for details.

Contact Information

Volunteer or get more information
Toll free: 1-800-411-1222
TTY: 1-866-411-1010
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Participating in Research

Watch a series of short informational videos about participating in clinical trials. These videos are intended to help potential participants understand how research works, what questions they should consider asking, and things to think about when deciding whether or not to participate in a study.

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