Proteome Exploration of Human Coronaviruses for Identifying Novel Vaccine Candidate: A Hierarchical Subtractive Genomics and Reverse Vaccinology Approach.

Background: The SARS-CoV-2 has been responsible for infecting more than 613,615,658 people in 222 countries by September 11, 2022, of which 6,516,076 have died. COVID-19 was introduced by World Health Organization as a global concern and a pandemic disease due to its prevalence.

Objective: Developing preventive or therapeutic medications against 2019-nCoV is an urgent need, and has been deemed as a high priority among scientific societies; in this regard, the production of effective vaccines is one of the most significant and high-priority requirements. Because of costly and time-consuming process of vaccine design, different immunoinformatics methods have been developed.

Methods: At the beginning of vaccine design, the proteome study is essential. In this investigation, the whole human coronavirus proteome was evaluated using the proteome subtraction strategy. Out of 5945 human coronavirus proteins, five new antigenic proteins were selected by analyzing the hierarchical proteome subtraction, and then their various physicochemical and immunological properties were investigated bioinformatically.

Results: All five protein sequences are antigenic and non-allergenic proteins; moreover, the spike protein group, including spike glycoprotein (E2) (Peplomer protein), spike fragment and spike glycoprotein fragment, showed acceptable stability, which can be used to design new vaccines against human coronaviruses.

Conclusion: The selected peptides and the other proteins introduced in this study (HE, orf7a, SARS_X4 domain-containing protein and protein 8) can be employed as a suitable candidate for developing a novel prophylactic or therapeutic vaccine against human coronaviruses.