Durable T-cellular and humoral responses in SARS-CoV-2 hospitalized and community patients

PLoS One. 2022 Feb 22;17(2):e0261979. doi: 10.1371/journal.pone.0261979. eCollection 2022.

Abstract

Background: Neutralizing antibodies are important for protection against the pandemic SARS-CoV-2 virus, and long-term memory responses determine the risk of re-infection or boosting after vaccination. T-cellular responses are considered important for partial protection against novel variants of concern.

Methods: A prospective cohort of hospitalized (n = 14) and community (n = 38) patients with rt-PCR confirmed SARS-CoV-2 infection were recruited. Blood samples and clinical data were collected when diagnosed and at 6 months. Serum samples were analyzed for SARS-CoV-2-spike specific antibodies using ELISA (IgG, IgA, IgM), pseudotype neutralization and microneutralization assays. Peripheral blood mononuclear cells were investigated for virus-specific T-cell responses in the interferon-γ and interleukin-2 fluorescent-linked immunosorbent spot (FluroSpot) assay.

Results: We found durable SARS-CoV-2 spike- and internal protein specific T-cellular responses in patients with persistent antibodies at 6 months. Significantly higher IL-2 and IFN-γ secreting T-cell responses as well as SARS-CoV-2 specific IgG and neutralizing antibodies were detected in hospitalized compared to community patients. The immune response was impacted by age, gender, comorbidity and severity of illness, reflecting clinical observations.

Conclusions: SARS-CoV-2 specific T-cellular and antibody responses persisted for 6 months post confirmed infection. In previously infected patients, re-exposure or vaccination will boost long-term immunity, possibly providing protection against re-infection with variant viruses.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Antibodies, Neutralizing / immunology*
  • Antibodies, Viral / immunology*
  • COVID-19 / immunology*
  • COVID-19 / mortality
  • COVID-19 / therapy
  • Female
  • Follow-Up Studies
  • Hospitalization
  • Humans
  • Immunity, Cellular*
  • Interferon-gamma / immunology
  • Interleukin-2 / immunology
  • Male
  • Middle Aged
  • Prospective Studies
  • Risk Factors
  • SARS-CoV-2 / immunology*
  • T-Lymphocytes / immunology*

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • IFNG protein, human
  • IL2 protein, human
  • Interleukin-2
  • Interferon-gamma

Grants and funding

This work was supported by the Trond Mohn Stiftelse (RJC, grant number, TMS2020TMT05), the Ministry of Health and Care Services, Norway; Helse Vest (RJC, grant number F-11628), the Norwegian Research Council Globvac (RJC, grant number 284930); the European Union (RJC, grant numbers EU IMI115672, FLUCOP, H2020 874866 INCENTIVE, H2020 101037867 Vaccelerate); the Faculty of Medicine, University of Bergen, Norway; and Nanomedicines Flunanoair (RJC, grant number ERA-NETet EuroNanoMed2 i JTC2016). RUHS/FHU receives support from Trond Mohn Stiftelse (TMS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.