In silico design and immunoinformatics assessment of a multiepitope vaccine targeting borealpox virus.

Borealpox virus is an emerging zoonotic pathogen with rising global prevalence and no approved vaccines or targeted treatments. This study aimed to design a multi-epitope subunit vaccine against Borealpox virus. The viral cell-surface binding protein was selected as the primary antigenic target due to its role in host-cell attachment. The finalized vaccine construct comprises 163 amino acids and includes β-defensin 3 as an adjuvant, a PADRE sequence, and suitable linkers to enhance immunogenicity. Structural prediction revealed a stable conformation, with 97.4% of residues located in the most favored regions of the Ramachandran plot. The vaccine exhibited a VaxiJen antigenicity score of 0.7089 and was predicted to be non-allergenic. Population coverage analysis indicated that the selected epitopes cover 96.22% of the global population. Five discontinuous B-cell epitopes were identified, with top scores reaching 0.823. Molecular docking demonstrated strong binding of the vaccine construct to both TLR2 and TLR4 receptors, with docking scores of - 1210.7 and - 321.55 for the TLR2-vaccine complex. Molecular dynamics simulations over 100 ns showed structural stability, with RMSD values ranging between 0.35 and 0.42 nm. Immune simulations predicted complete antigen clearance by day 7, accompanied by robust IgM and IgG1 responses and elevated IFN-γ and IL-2 levels. Codon optimization achieved an optimal GC content of 48.47% for Escherichia coli expression, and in silico cloning showed successful vector insertion. Further in vitro and in vivo studies are required to validate the vaccine protective efficacy and safety.