BackgroundCharacterizing the
longevity and
quality of
cellular immune responses to
SARS-CoV-2 is critical to
understanding immunologic approaches to
protection against COVID-19. Prior studies suggest
SARS-CoV-2-specific
T cells are present in peripheral
blood 10 months after
infection. Further
analysis of the function, durability, and diversity of the cellular response long after natural
infection, over a wider range of ages and
disease phenotypes, is needed to further identify preventative and
therapeutic interventions. MethodsWe identified participants in our multi-site longitudinal, prospective
cohort study 12-months post SARS-CoV-2 infection representing a range of
disease severity. We investigated the function,
phenotypes, and frequency of
T cells specific for
SARS-CoV-2 using intracellular
cytokine staining and spectral
flow cytometry. In parallel, the
magnitude of
SARS-CoV-2-specific
antibodies was compared. ResultsSARS-CoV-2-specific
antibodies and
T cells were detected at 12-months post-
infection. Severity of acute illness was associated with higher frequencies of
SARS-CoV-2-specific CD4
T cells and
antibodies at 12-months. In contrast, polyfunctional and cytotoxic
T cells responsive to
SARS-CoV-2 were identified in participants over a wide spectrum of
disease severity. ConclusionsOur data show that SARS-CoV-2 infection induces polyfunctional
memory T cells detectable at 12-months post-
infection, with higher frequency noted in those
who originally experienced severe
disease.