Scientists compare Covid-19 to related viruses to help find vaccines 

In September 2020, scientists in Mali compared genetic information from the Covid-19 virus to 2 closely related coronaviruses to identify features that could help in vaccine development.

At the time, scientists were still searching for  successful Covid-19 vaccines. They wanted to identify mutations in the Covid-19 virus that could play a role in infection. The Malian researchers therefore compared the Covid-19 virus (SARS-CoV-2) to two other coronaviruses that cause disease in humans, namely MERS-CoV and SARS-CoV.

One of the main aims of the study was to identify specific areas on the Covid-19 virus, called epitopes, that can be recognized by the human immune system. Identifying them can help scientists to create more effective vaccines. The researchers also compared all three viruses to see whether there were genetic similarities that could further help in vaccine development.

They focussed on the genetic sequence of the viruses’ spike proteins, which are the proteins responsible for helping coronaviruses bind to, and infect, human cells.

What the researchers found was that the spike proteins of all three viruses were very genetically similar, especially the parts that interact with human cells. What stood out about the Covid-19 virus was that there were some slight changes in the spike protein that could make the virus more efficient at binding to human cells.

The findings from this study may allow other researchers to develop more effective Covid-19 vaccines by helping them to identify areas on the virus that are good targets for vaccines. The study also provided new information about the genetic similarities and differences between the Covid-19 virus and other coronaviruses. 

The researchers noted that future research should focus on whether genetic differences in the Covid-19 virus make it more infective and more dangerous than other coronaviruses.

Abstract

Background: Coronaviruses are normally specific to an animal taxon as host, mammals or birds depending on their species; however, these viruses can sometimes change host as a result of mutation. The HCoV-229E is one of six human coronaviruses that include HCoV-NL63, HCoV-OC43, HCoV-HKU1, MERS-CoV and SARSr-CoV (SARSr-CoV-1 and SARS-CoV2) and is distributed globally. MERS-CoV and SARS-CoV-2 could persist on inanimate surface like (metal, glass or plastic for up to nine days) (Huang, C.-L, 2020). Preventive measures and drug treatment with hydrochloroquine are useful, but a good effective vaccine may be needed to stop propagation of the covid-19 pandemic. The aim of our study was to identifiy vaccine candidate epitopes by bioinformatics approaches. Materials and Method: The complete genomic sequences of SARS-CoV-2 were obtained from 2019 Novel Coronavirus Resource (2019nCoVR) and two databases, including the National Center for Biotechnology Information (NCBI) Global Initiative on Sharing All Influenza Data (GISAID) and TAURAU/T-bio-infoserver for online bioinformatics. we will provide a brief review of viral origin, compare the sequencing data for conserved region identification, his commonest protein domain( target binding site) and consensus motif design for an potential candidate molecule (epitope) prurposition for treatment strategies for the newly identified 2019-nCoV , SARSr-CoV strain and MERS-CoV. Results: Interestingly, sequence comparison between SARS-CoV-2 and another strain revealed that the residues present in the receptor-interacting motive are highly conserved with 70 % identity. we funded five important amino acids ( L455, Y473, N479, F486, Q493) on the receptor binding domain from spike proteins responsible of contact between virus and horst . In the SARS-CoV_ RBD are present residues (D480, and T487) that allowed the interspecies infection. However, in SARS-CoV-2, slight modification of some residues could improve the interaction with the human cellular receptor: L455, F486, Q493, and N501. In SARS-CoV, two main residues (479 and 487) have been associated to the recognition of the human ACE2 receptor. In the SARS-CoV-2, the residues corresponding to N479 correspond to Q493 and T487 to N501. These changes in the SARS-CoV-2 represent energetically favorable changes for the interaction with the receptor. we identified the sequences of amino acids that are well conserved across many coronaviruses including 2019nCoV and other strains, the motif KRSFIEDLLFNKVTLADAGF was found to be particularly well-conserved in this study and corresponds to the region around one of the known cleavage sites of the SARS virus that are believed to be required for virus activation for cell entry. This sequence motif and surrounding variations formed the basis for proposing a specific synthetic vaccine epitope this finding can make related likely rigid small molecule candidates and binding targets. Conclusion: This study provides information and opportunities for biological confirmation. The work can nevertheless be described in bioinformatics terms, and easily replicated by others, although new data and research on Covid-19 are emerging and evolving at an explosive rhythm.

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