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

Background: 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. Objective: To study the immune response of people who receive Pizer or Moderna COVID-19 vaccines. Eligibility: 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. Design: 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.

NCT Number	NCT04852289
Lead Sponsor	National Institute on Aging (NIA)
Conditions	COVID-19
Enrollment	78 participants
Start Date	2021-04-20
Primary Completion	2026-12-31 (estimated)
Study Completion	2027-06-30 (estimated)
Updated on ClinicalTrials.gov	2026-07-09