Exposure to SARS-CoV-2 generates T-cell memory in the absence of a detectable viral infection

Nat Commun. 2021 Mar 19;12(1):1724. doi: 10.1038/s41467-021-22036-z.

Abstract

T-cell immunity is important for recovery from COVID-19 and provides heightened immunity for re-infection. However, little is known about the SARS-CoV-2-specific T-cell immunity in virus-exposed individuals. Here we report virus-specific CD4+ and CD8+ T-cell memory in recovered COVID-19 patients and close contacts. We also demonstrate the size and quality of the memory T-cell pool of COVID-19 patients are larger and better than those of close contacts. However, the proliferation capacity, size and quality of T-cell responses in close contacts are readily distinguishable from healthy donors, suggesting close contacts are able to gain T-cell immunity against SARS-CoV-2 despite lacking a detectable infection. Additionally, asymptomatic and symptomatic COVID-19 patients contain similar levels of SARS-CoV-2-specific T-cell memory. Overall, this study demonstrates the versatility and potential of memory T cells from COVID-19 patients and close contacts, which may be important for host protection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Viral / immunology
  • Asymptomatic Infections
  • CD4-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • COVID-19 / blood
  • COVID-19 / immunology*
  • Case-Control Studies
  • Humans
  • Immunologic Memory / immunology*
  • Interferon-gamma / biosynthesis
  • Interferon-gamma / immunology
  • SARS-CoV-2 / immunology*
  • Virus Diseases / diagnosis*

Substances

  • Antibodies, Viral
  • Interferon-gamma