Frontiers in Immunology (Mar 2023)

Low humoral and cellular immune responses early after breakthrough infection may contribute to severe COVID-19

  • Chan Mi Lee,
  • Chan Mi Lee,
  • Pyoeng Gyun Choe,
  • Pyoeng Gyun Choe,
  • Chang Kyung Kang,
  • Chang Kyung Kang,
  • Eunyoung Lee,
  • Eunyoung Lee,
  • Kyoung-Ho Song,
  • Kyoung-Ho Song,
  • Ji Hwan Bang,
  • Ji Hwan Bang,
  • Eu Suk Kim,
  • Eu Suk Kim,
  • Hong Bin Kim,
  • Hong Bin Kim,
  • Nam Joong Kim,
  • Nam Joong Kim,
  • Hang-Rae Kim,
  • Hang-Rae Kim,
  • Youngju Kim,
  • Youngju Kim,
  • Chang-Han Lee,
  • Chang-Han Lee,
  • Chang-Han Lee,
  • Hyun Mu Shin,
  • Hyun Mu Shin,
  • Hyun Mu Shin,
  • Sang-Won Park,
  • Sang-Won Park,
  • Wan Beom Park,
  • Wan Beom Park,
  • Myoung-don Oh,
  • Myoung-don Oh

DOI
https://doi.org/10.3389/fimmu.2023.1106664
Journal volume & issue
Vol. 14

Abstract

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BackgroundLittle is known about the immune determinants for severe coronavirus disease 2019 (COVID-19) in individuals vaccinated against severe acute respiratory syndrome coronavirus 2. We therefore attempted to identify differences in humoral and cellular immune responses between patients with non-severe and severe breakthrough COVID-19.MethodsWe prospectively enrolled hospitalized patients with breakthrough COVID-19 (severe and non-severe groups) and uninfected individuals who were vaccinated at a similar time (control group). Severe cases were defined as those who required oxygen therapy while hospitalized. Enzyme-linked immunosorbent assays and flow cytometry were used to evaluate humoral and cellular immune responses, respectively.ResultsAnti-S1 IgG titers were significantly lower in the severe group than in the non-severe group within 1 week of symptom onset and higher in the non-severe group than in the control group. Compared with the control group, the cellular immune response tended to be diminished in breakthrough cases, particularly in the severe group. In multivariate analysis, advanced age and low anti-S1 IgG titer were associated with severe breakthrough COVID-19.ConclusionsSevere breakthrough COVID-19 might be attributed by low humoral and cellular immune responses early after infection. In the vaccinated population, delayed humoral and cellular immune responses may contribute to severe breakthrough COVID-19.

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