Frontiers in Immunology (Jan 2023)

Persistent humoral and CD4+ TH cell immunity after mild SARS-COV-2 infection—The CoNAN long-term study

  • Clara Schnizer,
  • Nico Andreas,
  • Wolfgang Vivas,
  • Wolfgang Vivas,
  • Wolfgang Vivas,
  • Thomas Kamradt,
  • Michael Baier,
  • Michael Kiehntopf,
  • Stefan Glöckner,
  • André Scherag,
  • Bettina Löffler,
  • Steffi Kolanos,
  • Joel Guerra,
  • Joel Guerra,
  • Mathias W. Pletz,
  • Mathias W. Pletz,
  • Sebastian Weis,
  • Sebastian Weis,
  • Sebastian Weis

DOI
https://doi.org/10.3389/fimmu.2022.1095129
Journal volume & issue
Vol. 13

Abstract

Read online

Understanding persistent cellular and humoral immune responses to SARS-CoV-2 will be of major importance to terminate the ongoing pandemic. Here, we assessed long-term immunity in individuals with mild COVID-19 up to 1 year after a localized SARS-CoV-2 outbreak. CoNAN was a longitudinal population-based cohort study performed 1.5 months, 6 months, and 12 months after a SARS-CoV-2 outbreak in a rural German community. We performed a time series of five different IgG immunoassays assessing SARS-CoV-2 antibody responses on serum samples from individuals that had been tested positive after a SARS-CoV-2 outbreak and in control individuals who had a negative PCR result. These analyses were complemented with the determination of spike-antigen specific TH cell responses in the same individuals. All infected participants were presented as asymptomatic or mild cases. Participants initially tested positive for SARS-CoV-2 infection either with PCR, antibody testing, or both had a rapid initial decline in the serum antibody levels in all serological tests but showed a persisting TH cell immunity as assessed by the detection of SARS-CoV-2 specificity of TH cells for up to 1 year after infection. Our data support the notion of a persistent T-cell immunity in mild and asymptomatic cases of SARS-CoV-2 up to 1 year after infection. We show that antibody titers decline over 1 year, but considering several test results, complete seroreversion is rare.Trial registrationGerman Clinical Trials Register DRKS00022416.

Keywords