In Silico Design of a Multivalent Epitope Vaccine Against SARS-CoV-2 for Iranian Populations

Background: Because of high genetic variation in human leukocyte antigen (HLA) alleles, epitope-based vaccines do not show equal efficacy in different human populations. Therefore, we proposed a multi-epitope vaccine against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) for Iranian populations. Materials and Methods: For this purpose, the proteins without allergenicity and high antigenicity, as well as conservancy levels from SARS-CoV-2, were chosen for computational epitope mapping. The T-cell epitope mapping process was performed based on the most frequent human leukocyte antigen (HLA) alleles in Iran. The B- and T-cell epitopes were determined based on their allergenicity, antigenicity, and hemolytic potential. Then, the epitopes with acceptable features were subjected to the final construct. The screened epitopes were structured in the final vaccine sequence. The secondary and tertiary structures of the proposed vaccine were predicted, and its affinity to HLA-I, HLA-II, toll-like receptor (TLR)- 3, and TLR-4 were evaluated by the molecular docking method. Additionally, possible immune responses against the vaccine were predicted through immune simulation. Results: The final vaccine construct includes six linear B-cell epitopes, eight HLA-I restricted epitopes, and six HLA-II restricted epitopes. The evaluations confirmed that the proposed vaccine is a 60.3 kDa stable, water-soluble, and high antigenic protein with high affinity to the selected target molecules and could elicit both humoral and cellular responses. Conclusion: Altogether, the study results suggest that the planned vaccine can be an adequate anti-COVID-19 vaccine candidate for the Iranian population.