Table 1_AI-guided epitope engineering of a SARS-CoV-2 spike antigen for broad sarbecovirus neutralization.docx

Here, we present a structure-guided, AI-enabled strategy for rational antigen design that enhances cross-reactive B-cell epitope recognition across betacoronaviruses. By integrating comparative sequence analysis with conformational epitope prediction, we identified conserved epitope hotspots within the Spike receptor-binding domain and introduced targeted motif-level substitutions into a SARS-CoV-2 BA.2 backbone.

Engineered Spike immunogens, delivered as mRNA-lipid nanoparticle vaccines, elicited robust antibody responses in mice and demonstrated broad neutralizing activity against antigenically diverse SARS-CoV-2 variants, including BA.5 and XBB.1.5, as well as zoonotic sarbecoviruses. Selected designs reached neutralisation breadth comparable to an Omicron-adapted clinical benchmark for shared SARS-CoV-2 antigens, while extending neutralising activity to divergent zoonotic sarbecoviruses.