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A Clinical Observational Study of SARS-CoV-2 Specific CD8 T-Cell Responses to COVID-19 Vaccines in Humans

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04852289
Recruitment Status : Recruiting
First Posted : April 21, 2021
Last Update Posted : July 7, 2022
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute on Aging (NIA) )

Brief Summary:


The immune response is how the body recognizes and defends itself against foreign and harmful substances. Researchers want to compare the immune responses between young and older healthy adults after they receive vaccine doses for COVID-19. This research may help to determine whether age impacts cell response to COVID-19 vaccines.


To study the immune response of people who receive Pizer or Moderna COVID-19 vaccines.


People aged 18 and older who have not had COVID-19 and who either plan to receive the first dose of a COVID-19 vaccine within the next month or have received at least the first of 2 doses of the vaccine within the last 6 months.


Participants will be screened by telephone.

Participants will not get the COVID-19 vaccine in this study. They must get it through a vaccine location.

Participants who have not yet been vaccinated will have 7 visits. The first 4 visits will occur in the first month before and after each vaccination. The last 3 visits will occur 6 months, 1 year, and 2 years after completed vaccination.

Participants who have received at least 1 of 2 doses of the COVID-19 vaccine within the last 6 months will have 3 visits. The first visit will occur within 6 months of receiving the first vaccine dose. The last 2 visits will occur 1 year and 2 years after the first vaccine dose.

At visits, participant will review their medical history. Their height, weight, and/or vital signs will be measured. They will give blood samples after fasting. They may give urine samples. They may have a nasal swab test for COVID-19.

Condition or disease

Detailed Description:


This study is to identify SARS-CoV-2 S protein specific CD8 T cells in the blood of COVID-19 vaccinated participants. Pfizer and Moderna made vaccines will be used in this study. As both vaccines are mRNA based encoding S protein of SARS-CoV-2 and require two doses, the CD8 T cell response is expected to be comparable. We will also measure general health factors using blood samples. By analyzing the frequency, differentiation, and expansion of these SARS-CoV-2 S protein specific CD8 T cells, we hope to shed light into the CD8 T cell response to COVID-19 vaccine and its change with age.


To determine the proportion of individuals who develop and maintain SARS-CoV-2 S protein specific CD8 T cells after vaccination as a proxy for cellular immunity to future SARS CoV-2 exposure and to determine if there are differences in CD8 T cell response to COVID-19 vaccines between young and older healthy adults.


Primary Endpoint: Presence or absence of various SARS-CoV-2 S protein specific CD8 T cells in COVID-19 vaccine participants and their quantitative changes during and after the course of vaccination.

Secondary Endpoint: Determining the effect of age (either prespecify age >65 vs <65 or explore as a continuous variable) and sex on presence of SARS-CoV-2 S protein specific CD8 T cells

Exploratory Endpoints:

  1. Correlations between CD8 T cell responses in vitro and circulating SARS-CoV-2 specific antibodies
  2. Plasma inflammatory cytokines and other biomarkers
  3. Collecting DNA from PBMCs for future genetic association studies, as an option for study participants.

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Study Type : Observational
Estimated Enrollment : 160 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: A Clinical Observational Study of SARS-CoV-2 Specific CD8 T-Cell Responses to COVID-19 Vaccines in Humans
Actual Study Start Date : April 20, 2021
Estimated Primary Completion Date : March 31, 2023
Estimated Study Completion Date : March 31, 2024

Resource links provided by the National Library of Medicine

>=65 Female
Older Females
>=65 Male
Older Males
18-64 Female
Young Females
18-64 Male
Young Males

Primary Outcome Measures :
  1. We are investigating the presence or absence of various SARS-CoV-2 specific CD8 T cells in healthy COVID-19 vaccinated participants to understand the composition of CD8 T cell immunity in COVID-19 pathogenesis. [ Time Frame: 4 months and one year data ]
    To determine quantitative changes of S protein specific CD8 T cells prior and post COVID-19 vaccination.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
The participants will consist of healthy men and women over 18 years of age who plan to have a COVID-19 vaccination within 30 days. An accrual ceiling of 160 participants will be recruited and screened until 140 eligible participants are enrolled, which are calculated based on four groups: young females (18-64), young males (18-64), old females (>=65), old males (>=65). Each group with 35 people to account for HLA-A2+, variations in HLA-A2 genotype percentage, and possible dropout. We will include both genders, 18 years of age and older, all races, and residents of the state of Maryland.

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

  1. Ability of subject to understand the study and stated willingness to comply with all study procedures and availability for the duration of the study.
  2. Male or female, aged 18 years or older.
  3. Willingness and ability to come to the NIH/National Institute on Aging Clinical Research Unit at MedStar Harbor Hospital or the NIH/NIA/Biomedical Research Center at Johns Hopkins Bayview campus in Baltimore for study procedures.
  4. Laboratory-confirmed negative tests for SARS-CoV-2 infection as determined by both of the following: Nasal turbinate swab (PCR) and Qualitative IgG Serology antibody testing.


An individual who meets any of the following criteria will be excluded from participation in this study:

  1. Unable to provide informed consent.
  2. Current use of steroids, immunosuppressive medications, radiation therapy, or chemotherapy medications.
  3. Pregnancy
  4. Received immunization therapy for COVID-19 prior to visit 1.

In addition, eligible participants may not be immediately able to participate in the study but might be eligible at a later date. These include:

  1. Symptoms of a viral infection on visit 1 (defer until resolved).
  2. Medication: Volunteers taking the following medications would be deferred for 2 weeks after course has been completed and volunteer is feeling well: Antibiotics, antifungals, antimalarials, antivirals.
  3. Temporary steroids (tapers): Deferred for 72 hours after symptoms are resolved and prescription is completed if taken orally, intravenously, or intramuscular. No deferral if taken intranasal, inhaled, or for joint injection.
  4. Infection or Fever: Deferred until 2 weeks after antibiotics are completed and /or volunteer is feeling well.
  5. We wish to only select healthy confirmed COVID-19 negative patients. Therefore, those who may have a household member (co-habitant) who is newly diagnosed with COVID-19 or who has symptoms will be deferred for 14 days.
  6. Treatment with another investigational drug or other intervention within 14 days of visit 1 per the discretion of the Principal Investigator.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04852289

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Contact: Julia L McKelvey, R.N. (410) 350-3929
Contact: Nan-Ping Weng, M.D. (410) 558-8341

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United States, Maryland
National Institute of Aging, Clinical Research Unit Recruiting
Baltimore, Maryland, United States, 21224
Contact: NIA Studies Recruitment    410-350-3941   
NIH/NIA/Biomedical Research Center at Johns Hopkins Bayview campus Recruiting
Baltimore, Maryland, United States, 21244
Sponsors and Collaborators
National Institute on Aging (NIA)
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Principal Investigator: Nan-Ping Weng, M.D. National Institute on Aging (NIA)
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Responsible Party: National Institute on Aging (NIA) Identifier: NCT04852289    
Other Study ID Numbers: 10000383
First Posted: April 21, 2021    Key Record Dates
Last Update Posted: July 7, 2022
Last Verified: June 15, 2022
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided
Plan Description: .We will deposit the research data to NCBI without individual identity information when the findings are written for publications.

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by National Institutes of Health Clinical Center (CC) ( National Institute on Aging (NIA) ):
Cellular Immune
Natural History
Additional relevant MeSH terms:
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Respiratory Tract Infections
Pneumonia, Viral
Virus Diseases
Coronavirus Infections
Coronaviridae Infections
Nidovirales Infections
RNA Virus Infections
Lung Diseases
Respiratory Tract Diseases