Back to Search
Start Over
Dynamics of T-cell Responses Following COVID-19 mRNA Vaccination and Breakthrough Infection in Older Adults.
- Source :
-
Pathogens & immunity [Pathog Immun] 2023 Nov 17; Vol. 8 (1), pp. 117-135. Date of Electronic Publication: 2023 Nov 17 (Print Publication: 2023). - Publication Year :
- 2023
-
Abstract
- Introduction: While older adults generally mount weaker antibody responses to a primary COVID-19 vaccine series, T-cell responses remain less well characterized in this population. We compared SARS-CoV-2 spike-specific T-cell responses after 2- and 3-dose COVID-19 mRNA vaccination and subsequent breakthrough infection in older and younger adults.<br />Methods: We quantified CD4+ and CD8+ T-cells reactive to overlapping peptides spanning the ancestral SARS-CoV-2 spike protein in 40 older adults (median age 79) and 50 younger health care workers (median age 39), all COVID-19 naive, using an activation-induced marker assay. T-cell responses were further assessed in 24 participants, including 8 older adults, who subsequently experienced their first SARS-CoV-2 breakthrough infection.<br />Results: A third COVID-19 mRNA vaccine dose significantly boosted spike-specific CD4+ and CD8+ T-cell frequencies to above 2-dose levels in older and younger adults. T-cell frequencies did not significantly differ between older and younger adults after either dose. Multivariable analyses adjusting for sociodemographic, health, and vaccine-related variables confirmed that older age was not associated with impaired cellular responses. Instead, the strongest predictors of CD4+ and CD8+ T-cell frequencies post-third-dose were their corresponding post-second-dose frequencies. Breakthrough infection significantly increased both CD4+ and CD8+ T-cell frequencies, to comparable levels in older and younger adults. Exploratory analyses revealed an association between HLA-A*02:03 and higher post-vaccination CD8+ T-cell frequencies, which may be attributable to numerous strong-binding HLA-A*02:03-specific CD8+ T-cell epitopes in the spike protein.<br />Conclusion: Older adults mount robust T-cell responses to 2- and 3-dose COVID-19 mRNA vaccination, which are further boosted following breakthrough infection.<br />Competing Interests: The authors report no conflicts of interest to declare.<br /> (Copyright © 2023 Pathogens and Immunity.)
Details
- Language :
- English
- ISSN :
- 2469-2964
- Volume :
- 8
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Pathogens & immunity
- Publication Type :
- Academic Journal
- Accession number :
- 38035132
- Full Text :
- https://doi.org/10.20411/pai.v8i1.613