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TerminatedNCT04892797Updated May 14, 2025

Understanding Immunology and Patient Outcomes of COVID-19 in Hospitalized Patients

An observational study in Covid19, sponsored by University of Vermont. Terminated at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-05-14.

Sponsored by University of Vermont · Observational

Why this study was terminated
Grant application to fund this work was not funded. We won't be posting data for this study.
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
16
Ages
18 Years and older
Sex
All
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Study summary

The adaptive immune response, consisting of antiviral T and B cells, is critical for providing protection against viruses such as SARS-CoV-2, both during an active infection and later following a subsequent exposure. They can both also potentially contribute to pathogenesis if they are overstimulated. Despite these advances in knowledge, there are still significant gaps in understanding of what constitutes a protective or immunopathologic immune response and its durability.

Significant knowledge gaps also remain pertaining to the early recognition of COVID patients with increased risk of clinical deterioration who require continued hospitalization and the use of more intensive treatments designed to improve outcomes. Data from non-COVID patients with MI show that platelet surface expression of FcγRIIa, the low-affinity receptor for the Fc fragment of immunoglobulin (Ig) G, identifies patients at high and low risk of subsequent cardiovascular events. Platelet expression of FcγRIIa is increased by interferon γ20 that is significantly elevated in severe COVID-19 infections. The high prevalence of arterial thrombosis among COVID-19 patients and the central role of thrombosis in respiratory failure support the hypothesis that elevated platelet expression of FcγRIIa will identify COVID patients at increased risk of thrombotic complications and clinical deterioration.

In addition to the potential role of platelet activation in thrombosis associated with COIVD-19, the endothelium may also play a significant role. The investigators hypothesize that elevated EMPs in plasma will identify patients at high risk of thrombosis and clinical deterioration.

To begin to address the knowledge gaps above and obtain preliminary data for future large grant submission, the investigators propose a small, prospective, single-center cohort study that will enroll patients hospitalized for COVID-19 infection and exhibiting a range of disease severity. Biosamples will be obtained and used to study T and B cells, antibody repertoire, and durability of protective immunity, and also to quantify platelet expression of FcγRIIa and circulating EMPs, as described in the protocol.

Read the detailed description

Since December 2019, the novel coronavirus (SARS-CoV-2) and associated COVID-19 illness has spread worldwide. Globally, there are >86 million infections and over 1.8 million confirmed deaths, with the pandemic continuing at record levels throughout the USA. While new data on COVID-19 are emerging daily, several knowledge gaps remain, including understanding of the adaptive immune response to infection, the propensity for infected patients to experience thrombotic events, and identification of biomarkers that might predict clinical deterioration.

The adaptive immune response, consisting of antiviral T and B cells, is critical for providing protection against viruses such as SARS-CoV-2, both during an active infection and later following a subsequent exposure. They can both also potentially contribute to pathogenesis if they are overstimulated. Much has been learned about the T and B cell responses to SARS-CoV-2 since the beginning of the COVID-19 pandemic. The most comprehensive study to date shows that most individuals make a balanced T and B cell response that persists for at least 8 months. Despite these advances in knowledge, there are still significant gaps in understanding of what constitutes a protective or immunopathologic immune response and their durability.

Significant knowledge gaps also remain pertaining to the early recognition of COVID patients with increased risk of clinical deterioration who require continued hospitalization and the use of more intensive treatments designed to improve outcomes. In addition, the identification of low risk patients who can be discharged from the hospital would reduce the use of potentially scarce medical resources, particularly during a surge. Among patients with thrombosis, 49% required critical care and 43% died. Data from non-COVID patients with MI show that platelet surface expression of FcγRIIa, the low-affinity receptor for the Fc fragment of immunoglobulin (Ig) G, identifies patients at high and low risk of subsequent cardiovascular events. Platelet expression of FcγRIIa is increased by interferon γ20 that is significantly elevated in severe COVID-19 infections. Because FcγRIIa amplifies platelet activation, greater expression of FcγRIIa on the surface of the platelet increases platelet reactivity. The high prevalence of arterial thrombosis among COVID-19 patients and the central role of thrombosis in respiratory failure support the hypothesis that elevated platelet expression of FcγRIIa will identify COVID patients at increased risk of thrombotic complications and clinical deterioration.

In addition to the potential role of platelet activation in thrombosis associated with COIVD-19, the endothelium may also play a significant role. The endothelium is a key site of entry for COVID-19 infection and endothelial injury contributes to thrombotic events that increase morbidity and mortality. Endothelial microparticles (EMPs), submicron membranous vesicles indicating endothelial activation and injury, are released by the endothelium into blood and reflect the competency of endothelial function by identifying endothelial activation and injury, which promote thrombosis. Circulating EMPs can be quantified with the use of flow cytometry. The investigators hypothesize that elevated EMPs in plasma will identify patients at high risk of thrombosis and clinical deterioration.

To begin to address the knowledge gaps above and obtain preliminary data for future large grant submission, the investigators propose a small, prospective, single-center cohort study that will enroll patients hospitalized for COVID-19 infection and exhibiting a range of disease severity. Blood will be obtained on study days 1, 3±1, 7±1 (and every 7±1 days thereafter up to day 28 while hospitalized), and again at 12 months of follow up. Nasopharyngeal (NP) swabs will be collected on these same study days through day 28, but not at 12 months. These biosamples will be used to study T and B cells, antibody repertoire, and durability of protective immunity, and also to quantify platelet expression of FcγRIIa and circulating EMPs, as described in the protocol.

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Conditions studied

  • Covid19

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03

In context

COVID-19

7,640 studies on the registry are indexed under COVID-19; 488 are open to participants now.

This study's enrollment of 16 is below the median of 261 across 3,136 observational studies indexed under COVID-19.

Browse COVID-19 studies →

Lead sponsor

University of Vermont is the lead sponsor of 215 studies on the registry; 28 are open to participants now.

Of its 16 completed or terminated interventional studies of FDA-regulated products, 9 (56%) have results posted.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

This study will enroll patients hospitalized at the University of Vermont Medical Center who have a positive test result for COVID-19. These patients are expected to have a greater acuity of illness and burden of disease based on the fact that they require inpatient care. Enrolling hospitalized patients ensures a greater opportunity to collect serial biological specimens over the course of the illness due to the proximity of the patient to medical and research staff and UVM laboratories.

Inclusion criteria

  1. Adult (≥18 years old) at the time of consent
  2. Positive COVID-19 PCR test result

Exclusion criteria

Exclusion Criteria:

  1. Expected death or withdrawal of life-sustaining treatments within 3 days
  2. Hemoglobin ≤7.0 at the time of consent
  3. Unable to provide consent and no legally authorized representative (LAR) identified or reached by phone
  4. Pregnant
  5. Incarcerated
  6. Physician declines patient enrollment (attending physician or study physician)
  7. Patient or LAR do not consent to participate in the study
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Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
16 participants (actual)
Patient registry
No
Biospecimen retention
Samples with dna

Groups and cohorts

  • Covid-19+

    Hospitalized patients with Covid-19 infection confirmed by PCR test

    Other: Covid-19+ observational

Interventions

  • OtherCovid-19+ observational

    This is observational--there is no intervention

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What researchers measure

Primary outcomes

  1. To compare the polyfunctionality and frequency of antiviral CD4 and CD8 T cells.

    The investigators hypothesize patients with severe disease will have higher frequencies of antiviral T cells that contribute to the cytokine storm observed in the most severe cases of COVID-19.

    Time frame: Four weeks (while hospitalized)

  2. To compare the polyfunctionality and frequency of antiviral CD4 and CD8 T cells.

    The investigators hypothesize patients with severe disease will have higher frequencies of antiviral T cells that contribute to the cytokine storm observed in the most severe cases of COVID-19.

    Time frame: 12 months after hospital admission

  3. To compare the frequency of plasmablasts (early B cells that produce antiviral antibodies) and plasma antiviral antibody titer during acute infection.

    The investigators predict that patients with severe disease will have greater numbers of antiviral plasmablasts and plasma antiviral antibody levels compared to those with mild disease.

    Time frame: Four weeks (while hospitalized)

  4. To compare the frequency of plasmablasts (early B cells that produce antiviral antibodies) and plasma antiviral antibody titer during acute infection.

    The investigators predict that patients with severe disease will have greater numbers of antiviral plasmablasts and plasma antiviral antibody levels compared to those with mild disease.

    Time frame: 12 months after hospital admission

  5. The number of virus specific CD4 T cells will be measured using flow cytometry.

    The investigators hypothesize that severe disease will result in the formation of higher magnitude antiviral B and T cell CHRMS (Medical) #STUDY00001369 Approved: 1/25/2021 4Human subjects protocol form 7/19/19responses during acute disease due to increased viral load and antigen in these patients. The investigators further predict that higher frequency T and B cells during acute disease will correlate with more robust durability of these responses during convalescence.

    Time frame: Four weeks (while hospitalized)

  6. The number of virus specific CD8 T cells will be measured using flow cytometry.

    The investigators hypothesize that severe disease will result in the formation of higher magnitude antiviral B and T cell CHRMS (Medical) #STUDY00001369 Approved: 1/25/2021 4Human subjects protocol form 7/19/19responses during acute disease due to increased viral load and antigen in these patients. The investigators further predict that higher frequency T and B cells during acute disease will correlate with more robust durability of these responses during convalescence.

    Time frame: Four weeks (while hospitalized)

  7. The number of virus specific CD4 T cells will be measured using flow cytometry.

    The investigators hypothesize that severe disease will result in the formation of higher magnitude antiviral B and T cell CHRMS (Medical) #STUDY00001369 Approved: 1/25/2021 4 Human subjects protocol form 7/19/19 responses during acute disease due to increased viral load and antigen in these patients. The investigators further predict that higher frequency T and B cells during acute disease will correlate with more robust durability of these responses during convalescence.

    Time frame: 12 months after hospital admission

  8. The number of virus specific CD8 T cells will be measured using flow cytometry.

    The investigators hypothesize that severe disease will result in the formation of higher magnitude antiviral B and T cell CHRMS (Medical) #STUDY00001369 Approved: 1/25/2021 4Human subjects protocol form 7/19/19responses during acute disease due to increased viral load and antigen in these patients. The investigators further predict that higher frequency T and B cells during acute disease will correlate with more robust durability of these responses during convalescence.

    Time frame: 12 months after hospital admission

  9. To obtain preliminary data on platelet activation in patients hospitalized with COVID-19

    To compare platelet activation, measured by platelet surface FcγRIIa while in hospital and 12 months after infection, in patients with severe (i.e., mechanical ventilation in ICU) vs. non-severe (hospitalized, but not in an ICU) COVID-19 disease.

    Time frame: Four weeks (while hospitalized)

  10. To obtain preliminary data on platelet activation in patients hospitalized with COVID-19

    To compare platelet activation, measured by platelet surface FcγRIIa while in hospital and 12 months after infection, in patients with severe (i.e., mechanical ventilation in ICU) vs. non-severe (hospitalized, but not in an ICU) COVID-19 disease.

    Time frame: 12 months after hospital admission

  11. To obtain preliminary data on endothelial activation in patients hospitalized with COVID-19

    To compare endothelial activation, measured by circulating EMPs while in hospital and 12 months after infection, in patients with severe (i.e., mechanical ventilation in ICU) vs. non-severe (hospitalized, but not in an ICU) COVID-19 disease.

    Time frame: Four weeks (while hospitalized)

  12. To obtain preliminary data on endothelial activation in patients hospitalized with COVID-19

    To compare endothelial activation, measured by circulating EMPs while in hospital and 12 months after infection, in patients with severe (i.e., mechanical ventilation in ICU) vs. non-severe (hospitalized, but not in an ICU) COVID-19 disease.

    Time frame: 12 months after hospital admission

  13. Preliminarily determine if the FcγRIIa and EMPs have utility as biomarkers

    To preliminarily determine if the FcγRIIa and EMPs have utility as biomarkers for prediction of thrombotic events and clinical deterioration in hospitalized patients with COVID-19.

    Time frame: Four weeks (while hospitalized)

  14. Preliminarily determine if the FcγRIIa and EMPs have utility as biomarkers

    To preliminarily determine if the FcγRIIa and EMPs have utility as biomarkers for prediction of thrombotic events and clinical deterioration in hospitalized patients with COVID-19.

    Time frame: 12 months after hospital admission

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Study locations

1 site
  • University of Vermont
    Burlington, Vermont 05405, United States
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References and documents

Individual participant data

Plan to share: Undecided

No publications or documents are linked to this record.

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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 14, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT04892797
Lead sponsor
University of Vermont
Responsible party
Renee Stapleton (Professor of Medicine, University of Vermont) — Principal investigator
First posted
May 19, 2021
Start date
Feb 3, 2021
Primary completion
Jun 30, 2023
Completion
Jun 30, 2023
Last update
May 14, 2025

Study contacts

Renee Stapleton, MD, PhD
principal investigator · University of Vermont

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is terminated, as verified in Feb 2025. You cannot join it, but the record below documents what was studied.

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