A computational approach for MHC-restricted multi-epitope vaccine design targeting Oropouche virus structural proteins

In recent years, Brazil has recorded approximately 500,000 Oropouche virus (OROV) cases in the Amazon region, underscoring the growing global threat posed by emerging and reemerging viruses. Symptoms of OROV closely resemble those of Dengue virus and Zika virus, contributing to underreporting and underestimation of its true impact. In the absence of specific treatments, the development of vaccines becomes essential. This study aimed to identify immunogenic epitopes in three structural proteins of OROV and develop a multi-epitope vaccine candidate. RefSeq sequences of the nucleocapsid protein and the Gn and Gc glycoproteins were obtained from the National Center for Biotechnology Information Virus and submitted to epitope search in Immune Epitope Database. Antigenicity, allergenicity, stability, and toxicity analyses were conducted, and the approved epitopes were aligned to the global protein to remove transmembrane regions and N-glycosylation sites. Thirteen epitopes were selected and used to construct a multi-epitope vaccine candidate, with beta-defensin and PADRE adjuvants. The protein demonstrated optimal antigenicity, low allergenicity, and satisfactory stability and solubility. Predictions of humoral and cellular immune responses were performed, indicating satisfactory results for three doses of the vaccine candidate. 3D modeling of the protein was performed, evaluating the molecular docking of the multi-epitope protein with TLR-2, TLR-3, TLR-6, and TLR-8 receptors. Our findings present a promising vaccine candidate against OROV, potentially protecting immunocompromised individuals and high-risk populations, and establishing a foundation for both in vitro and in vivo testing. The identified epitopes could also aid in immunodiagnostic test development, advancing surveillance and control strategies.