Engineering a broad-spectrum vaccine to combat emerging monkeypox virus via immunoinformatic approaches

Monkeypox virus (MPXV) has caused 41,664 confirmed cases and five deaths in nonendemic 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 vaccination approach could be used as a promising tool for designing effective and safe vaccines against MPXV. Here, the associations of MPXV proteins 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 the vaccine constructs were further computationally validated for their 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 ultimately cloned in silico into the pET21a(+) vector. Collectively, these results could lead to the use of innovative tools for vaccine formulation against MPXV and for the treatment of other infectious diseases.