Persistence of T Cell and Antibody Responses to SARS-CoV-2 Up to 9 Months after Symptom Onset

J Immunol. 2022 Jan 15;208(2):429-443. doi: 10.4049/jimmunol.2100727. Epub 2021 Dec 13.


Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces T cell, B cell, and Ab responses that are detected for several months in recovered individuals. Whether this response resembles a typical respiratory viral infection is a matter of debate. In this study, we followed T cell and Ab responses in 24 mainly nonhospitalized human subjects who had recovered from PCR-confirmed SARS-CoV-2 infection at two time points (median of 45 and 145 d after symptom onset). Ab responses were detected in 95% of subjects, with a strong correlation between plasma and salivary anti-spike (anti-S) and anti-receptor binding domain IgG, as well as a correlation between circulating T follicular helper cells and the SARS-CoV-2-specific IgG response. T cell responses to SARS-CoV-2 peptides were determined using intracellular cytokine staining, activation markers, proliferation, and cytokine secretion. All study subjects had a T cell response to at least one SARS-CoV-2 Ag based on at least one T cell assay. CD4+ responses were largely of the Th1 phenotype, but with a lower ratio of IFN-γ- to IL-2-producing cells and a lower frequency of CD8+:CD4+ T cells than in influenza A virus (IAV)-specific memory responses within the same subjects. Analysis of secreted molecules also revealed a lower ratio of IFN-γ to IL-2 and an altered cytotoxic profile for SARS-CoV-2 S- and nucleocapsid-specific responses compared with IAV-specific responses. These data suggest that the memory T cell phenotype after a single infection with SARS-CoV-2 persists over time, with an altered cytokine and cytotoxicity profile compared with long-term memory to whole IAV within the same subjects.

Publication types

  • Research Support, Non-U.S. Gov't
  • Observational Study

MeSH terms

  • Adult
  • Aged
  • Antibody Formation*
  • COVID-19 / immunology*
  • Female
  • Humans
  • Immunity, Cellular*
  • Immunoglobulin G / immunology*
  • Male
  • Middle Aged
  • SARS-CoV-2 / immunology*
  • Spike Glycoprotein, Coronavirus / immunology*
  • Th1 Cells / immunology*
  • Time Factors


  • Immunoglobulin G
  • Spike Glycoprotein, Coronavirus
  • spike protein, SARS-CoV-2