Engineering a broad-spectrum multi-epitope vaccine to combat emerging monkeypox virus by immunoinformatic approaches

Monkeypox virus (MPXV), has caused 41,664 confirmed cases and five deaths in non-endemic regions, as reported by the World Health Organization (WHO). There is an urgent demand for effective vaccines to combat and prevent the spread of MPXV. Traditional vaccine development is low-throughput, expensive, time-consuming, and susceptible to reversion to virulence. As an alternative, a reverse vaccinology approach can be employed as a promising tool to design effective and safe vaccines against MPXV. Here, MPXV proteins associated with viral infection were analyzed for potential immunogenic epitopes to design multi-epitope vaccine constructs based on B-cell, CD4+, and CD8+ epitopes. Epitopes were selected based on allergenicity, antigenicity, and toxicity parameters. The prioritized epitopes were then combined via peptide linkers and N-terminally fused to various protein adjuvants, including PADRE, beta-defensin 3, 50S ribosomal protein L7/12, RS-09, and the cholera toxin B subunit (CTB). All vaccine constructs were further computationally validated for physicochemical properties, antigenicity potential, allergenicity, safety, solubility, and structural stability. The three-dimensional structure of the selected construct was also predicted. Moreover, molecular docking and molecular dynamics (MD) simulations between the vaccine and the TLR-4 immune receptor demonstrated a strong and stable interaction. The vaccine construct was codon-optimized for high expression in the E. coli platform and was finally cloned in silico into the pET21a(+) vector. Collectively, these results could represent innovative tools for vaccine formulation against MPXV and be transformative for other infectious diseases.