Frontiers in Immunology (Aug 2022)

Protective antigenic epitopes revealed by immunosignatures after three doses of inactivated SARS-CoV-2 vaccine

  • Mian Peng,
  • Mian Peng,
  • Mian Peng,
  • Xiaowen Dou,
  • Xiuming Zhang,
  • Mingchen Yan,
  • Dan Xiong,
  • Ruiwei Jiang,
  • Tong Ou,
  • Aifa Tang,
  • Xiqiu Yu,
  • Feiqi Zhu,
  • Weiqin Li,
  • Weiqin Li

DOI
https://doi.org/10.3389/fimmu.2022.938378
Journal volume & issue
Vol. 13

Abstract

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BackgroundSARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) has infected millions of people around the world. Vaccination is a pillar in the strategy to control transmission of the SARS-CoV-2 spread. Immune responses to vaccination require elucidation.MethodsThe immune responses to vaccination with three doses of inactivated SARS-CoV-2 vaccine were followed in a cohort of 37 healthy adults (18–59 years old). Blood samples were collected at multiple time points and submitted to peptide array, machine learning modeling, and sequence alignment analyses, the results of which were used to generate vaccine-induced antibody-binding region (VIABR) immunosignatures (Registration number: ChiCTR2200058571).ResultsAntibody spectrum signals showed vaccination stimulated antibody production. Sequence alignment analyses revealed that a third vaccine dose generated a new highly represented VIABR near the A570D mutation, and the whole process of inoculation enhanced the VIABR near the N501Y mutation. In addition, the antigen conformational epitopes varied between short- and long-term samples. The amino acids with the highest scores in the short-term samples were distributed primarily in the receptor binding domain (RBD) and N-terminal domain regions of spike (S) protein, while in the long-term samples (12 weeks after the 2nd dose), some new conformational epitopes (CEs) were localized to crevices within the head of the S protein trimer.ConclusionProtective antigenic epitopes were revealed by immunosignatures after three doses of inactivated SARS-CoV-2 vaccine inoculation. A third dose results in a new top-10 VIABR near the A570D mutation site of S protein, and the whole process of inoculation enhanced the VIABR near the N501Y mutation, thus potentially providing protection from strains that have gained invasion and immune escape abilities through these mutation.

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