PLoS ONE (Jan 2023)

Severe and mild-moderate SARS-CoV-2 vaccinated patients show different frequencies of IFNγ-releasing cells: An exploratory study.

  • Eugenio Garofalo,
  • Flavia Biamonte,
  • Camillo Palmieri,
  • Anna Martina Battaglia,
  • Alessandro Sacco,
  • Eugenio Biamonte,
  • Giuseppe Neri,
  • Giulio Cesare Antico,
  • Serafina Mancuso,
  • Giuseppe Foti,
  • Carlo Torti,
  • Francesco Saverio Costanzo,
  • Federico Longhini,
  • Andrea Bruni

DOI
https://doi.org/10.1371/journal.pone.0281444
Journal volume & issue
Vol. 18, no. 2
p. e0281444

Abstract

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BackgroundDespite an apparent effective vaccination, some patients are admitted to the hospital after SARS-CoV-2 infection. The role of adaptive immunity in COVID-19 is growing; nonetheless, differences in the spike-specific immune responses between patients requiring or not hospitalization for SARS-CoV-2 infection remains to be evaluated. In this study, we aim to evaluate the spike-specific immune response in patients with mild-moderate or severeSARS-CoV-2 infection, after breakthrough infection following two doses of BNT162b2 mRNA vaccine.MethodsWe included three cohorts of 15 cases which received the two BNT162b2 vaccine doses in previous 4 to 7 months: 1) patients with severe COVID-19; 2) patients with mild-moderate COVID-19 and 3) vaccinated individuals with a negative SARS-CoV-2 molecular pharyngeal swab (healthy subjects). Anti-S1 and anti-S2 specific SARS-CoV-2 IgM and IgG titers were measured through a chemiluminescence immunoassay technology. In addition, the frequencies of IFNγ-releasing cells were measured by ELISpot.ResultsThe spike-specific IFNγ-releasing cells were significantly lower in severe patients (8 [0; 26] s.f.c.×106), as compared to mild-moderate patients (135 [64; 159] s.f.c.×106; p 81.2 x 106.Conclusions2-doses vaccinated patients requiring hospitalization for severe COVID-19 show a cellular-mediated immune response lower than mild-moderate or healthy subjects, despite similar antibody titers.