Abstract
Although the protective role of neutralizing antibodies against COVID-19 is well established, questions remain about the relative importance of cellular immunity. Using 6 pMHC multimers in a cohort with early and frequent sampling, we define the phenotype and kinetics of recalled and primary T cell responses following Delta or Omicron breakthrough infection in previously vaccinated individuals. Recall of spike-specific CD4+ T cells was rapid, with cellular proliferation and extensive activation evident as early as 1 day post symptom onset. Similarly, spike-specific CD8+ T cells were rapidly activated but showed variable degrees of expansion. The frequency of activated SARS-CoV-2-specific CD8+ T cells at baseline and peak inversely correlated with peak SARS-CoV-2 RNA levels in nasal swabs and accelerated viral clearance. Our study demonstrates that a rapid and extensive recall of memory T cell populations occurs early after breakthrough infection and suggests that CD8+ T cells contribute to the control of viral replication in breakthrough SARS-CoV-2 infections.
Original language | English |
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Pages (from-to) | 879-892.e4 |
Journal | Immunity |
Volume | 56 |
Issue number | 4 |
DOIs | |
Publication status | Published - 11 Apr 2023 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2023 Elsevier Inc.
Keywords
- breakthrough infection
- CD4 T cell immunity
- CD8 T cell immunity
- COVID-19 vaccines
- Delta
- multimer
- Omicron
- SARS-CoV-2
- T cell
- vaccination