Immune imprinting | Nature Immunology

The emergence of SARS-CoV-2 variants requires informed vaccine strategies. In Nature, Yisimayi et al. show that repeated Omicron exposure mitigates the immune imprinting conferred by ancestral (‘WT’) SARS-CoV-2 exposure. Mice vaccinated with WT SARS-CoV-2 (CoronaVac) that received one booster of BA.1, BA.5, BQ.1.1 or XBB mRNA vaccines had lower serum NT₅₀ (50% neutralizing titer) values against the corresponding boosting variants as the antigenic distance between the boosting variant and WT SARS-CoV-2 increased, which is suggestive of immune imprinting. A second mRNA vaccine booster…