Repeated Omicron exposures override ancestral SARS-CoV-2 immune imprinting

. Vaccination strategies to counter immune imprinting are critically needed. Here we investigated the degree and dynamics of immune imprinting in mouse models and human cohorts, especially focusing on the role of repeated Omicron stimulation. In mice, the efficacy of single Omicron boosting is heavily limited when using variants that are antigenically distinct from WT-such as the XBB variant-and this concerning situation could be mitigated by a second Omicron booster. Similarly, in humans, repeated Omicron infections could alleviate WT vaccination-induced immune imprinting and generate broad neutralization responses in both plasma and nasal mucosa. Notably, deep mutational scanning-based epitope…

• TM
  Tianjin Municipal Health Commission
• NN
  National Natural Science Foundation of China

  Award: 32222030
• CM
  Capital Medical University
• PU
  Peking University