Sep, 2021 - By WMR
A study conducted by a team of researchers from the University of Melbourne studied whether the emergence of more deadly variants of concern (VOCs) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is related to an increase in evolutionary rate.
The outbreak of COVID-19 has posed challenge to the healthcare sector globally. With the progression of pandemic, many new variants of SARS-CoV-2 such as Alpha, Delta, and others have emerged continuously. As the variants circulated across countries, issues pertaining to public health became major concern globally. In this context, it is important to note that the global death count from the COVID-19 pandemic is 4.43 million as of August 23, 2021. Thus, this statistics demands the need to maintain constant viral surveillance to identify newly emerging variants of SARS-CoV-2. For instance, whole-genome sequencing analysis is significant for monitoring evolution and epidemiology of SARS-CoV-2 and its variants. Factors such as transmissibility, immunogenicity, and infectivity are taken into consideration to understand the evolution of virus. As the pandemic progressed, variants of concern such as Alpha, Beta, Gamma, and Delta were reported which created havoc across various countries globally. These VOCs are characterized by a number of defined mutations such as N501Y and D614G mutations in the S protein or spike protein. For this study, the researchers considered data from the Global Initiative on Sharing Avian Influenza Data (GISAID). They interpreted genetic sequences of SARS-CoV-2 from the GISAID database. They considered various molecular clock models such as strict molecular clock, uncorrelated relaxed clock, and others. These clock models can estimate the evolutionary rate in phylogenetic trees.
In a nutshell, the study shed light on the significance of genomic surveillance data and phylogenetic methods for finding the evolutionary rates of viral VOCs. The researchers stress on the urgency of detecting VOC at an early stage and then analyzing the conditions that favor the emergence of new VOC.