SARS-CoV-2: Camazotz's Curse

Abstract

The world is currently face to face with a pandemic which is spreading rapidly across the globe caused by SARS-CoV-2, a strain of Coronaviruses (CoVs) belonging to subgenus Sarbecovirus of genus Betacoronavirus. World Health Organisation (WHO) on 11 Feb 20 named this disease caused by SARS-CoV-2 as Covid-19. This pandemic is spreading rapidly and more than 20,00,000 cases have occurred globally. The human Coronaviruses discovered in 1960s were considered potentially harmless endemic viruses with seasonal distribution before late 2002. The CoVs are found in a large number of domestic and wild animals and birds. The first pandemic caused by Coronavirus caused by SARS-CoV was recognized in the late 2002 in Guangdong Province and resulted in widespread morbidity and mortality. This was followed by MERS-CoV which began in 2012 in the Arabian peninsula with multiple outbreaks related to it in various parts of the globe. Various studies have suggested how these viruses made their entry from their natural reservoir bats via intermediate host like civets and camels in case of SARS-CoV and MERS-CoV respectively. The intermediate host of the SARS-CoV-2 still needs to be established. The SARS-CoV-2 has 96.2% similarity to the bat Severe Acute Respiratory Syndrome related-Coronavirus (SARSr-CoV RaTG13). SARS-CoV-2 has been found to be more distant in relation to SARS-CoV (79%) and MERS-CoV (50%). At the whole genome sequence level pangolin CoV and SARSr-CoV RaTG13 show 91.02% and 96.2% similarity with SARS-CoV-2 but the S1 subunit of spike protein of pangolin CoV is more closely related to SARS-CoV-2 than SARSr-CoV RaTG13. The genetic analysis of the currently circulating strains of the pandemic have shown 99.98-100% similarity in their genomes implying a recent shift to humans. The animal source of SARS-CoV-2 needs to be identified to implement control measures in the present pandemic. Also, how the virus moves interspecies will help predict and prevent future pandemics.

Understanding the SARS-CoV-2 to Manage COVID-19

“…4 Comparative genome analyses of SARS-CoV-2 with Coronaviruses from bats and pangolins show 96.2% and 91% similarity, respectively. 5 These studies suggest a high possibility of the virus to have originated or come through bats and pangolins.…”

Update of the current knowledge on genetics, evolution, immunopathogenesis, and transmission for coronavirus disease 19 (COVID-19)

“…Proteins from SARS and SARS-CoV-2 were treated as homologous: identity value > 65%, query coverage, >95% [160]. SARS-CoV-2 has been found to be more distant in relation to SARS-CoV (79%) and MERS-CoV (50%) [161]. Anand et al found that all sequences showed ~99.98% similarity in the nucleotide sequences, implying a relationship between the currently circulating viruses and suggesting a recent shift to humans [161].…”

“…Other studies have shown that the homology with a coronavirus strain isolated from pangolin was 99%, suggesting that SARS-CoV-2 might have originated from bat and pangolin might have served as the intermediate host between bat and human [165]. The genetic analysis of the currently circulating strains of the pandemic have shown 99.98-100% similarity in their genomes, implying a recent shift to humans [161]. Description of the epitopes distribution over the viral population might provide valuable information driving future researches aimed at setting efficient prophylactic strategies and/or the design of tool capable of differential diagnosis on the basis of serological tests.…”

Testing and surveillance strategies in the context of COVID-19 in India

“…Even prior to the current pandemic, some of the earlier known coronaviruses have been transmitted from civet cats and dromedary camels although their spread has not been as prevalent. These viruses cause a range of diseases from mild cold to infections with high mortality such as Severe Acute Respiratory Syndrome (SARS) or Middle East Respiratory Syndrome (MERS) [6,7].…”