Changing Dynamics of SARS-CoV-2: A Global Challenge

Abstract

Since November 2019, SARS-CoV-2 has been a matter of global concern due to its rapid spread, the millions of deaths it caused, and repeated waves of infections. One after another, many variants of this novel virus have come into existence due to its constant mutability, specifically in the spike glycoprotein region. The tally for variants of concern (VOCs), which already include Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1) and Delta (B.1.617.2), has increased to five with the latest appearance of Omicron (B.1.1.529). In our study, we examine the effect of the transmissibility and infectious potential of the virus due to various mutations of SARS-CoV-2, especially in the receptor-binding domain (RBD). We discuss the role of genome sequencing in tracing all the mutations and the importance of the R value (reproductive number) to understand the virus spread. We also review the effectiveness of the available vaccines on the variants of concern, as the rapid spread of the newly emergent Omicron variant has raised doubts about the usefulness of the current vaccines. The use of a mixed vaccination strategy has proved to be effective, yet the newer variants, such as Omicron, demand booster doses for the population. Multivalent immunogens could be considered as the plausible solution for conferring protection against potential new mutants of the virus in the future.

Genomic Epidemiology of the SARS-CoV-2 Epidemic in Cyprus from November 2020 to October 2021: The Passage of Waves of Alpha and Delta Variants of Concern

“…Many of the abovementioned mutations, such as (but not limited to) ΔH69/V70, L452R, T478K, N501Y, and P681H [ 108 ], have reoccurred in a number of lineages, and their combination may confer an even more increased transmission potential to an emerging variant. Such was the case for the Omicron VOC, which incorporates over 30 S gene mutations and became the most dominant variant around the world, including Cyprus (Manuscript in preparation), soon after its detection during November 2021 [ 109 ].…”

Role of CCL2/CCR2 axis in the pathogenesis of COVID-19 and possible Treatments: All options on the Table

“…In addition to Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), and Delta (B.1.617.2) SARS-CoV-2 variants of concern (VOCs), Omicron (B.1.1.529) has been added to the list [143] . The lineages B.1.1.7, recognized first in the United Kingdom, and B.1.351, recognized first in South Africa, have been categorized as VOCs according to the transmissibility, disease severity, and immune escape capability [144] , [145] .…”

Comparative docking studies of drugs and phytocompounds for emerging variants of SARS-CoV-2

“…To understand the genesis of novel variants, research has focused on the Spike glycoprotein. The Spike protein's RBD region mutations can make closer contact with hACE2, which results in a stronger binding affinity and probably enhanced VOCs infectivity (Chugh et al 2022). Among all the previously circulating VOCs, the Delta variant, has shown adverse effects on patients and has caused twice as many hospitalizations (Edara et al 2021).…”

“…COVID-19 has surfed successive waves in the preceding two years, with new variants surfacing one after the other, leaving the infection vulnerable to rumours because of its poor understanding (Maher et al 2021). According to the World Health Organisation, there have been a total of 5 Variants of Concern (VOCs), namely Alpha, Beta, Gamma, Delta and Omicron (Chugh et al 2022).…”

“…In this study, various drugs and phytocompounds have been selected for molecular docking with Spike glycoprotein, a trimeric club shaped structural protein of the SARS-CoV-2 virus, which facilitates viral fusion with the host cell (Chugh et al 2022). As Spike gene has a nucleotide mutation rate of 8.066 × 10 -4 substitutions per site per year, while the SARS-CoV-2 genome has a rate of 6.677 × 10 -4 substitutions per site per year, so certain mutations, particularly in the Spike glycoprotein, have been believed to enhance viral infectivity and transmissibility, resulting in emergence of several variants classified as Variants of Concern (VOC) and Variants of Interest (VOI) by the World Health Organization (Hu et al 2021;Wang et al 2020;Singh et al 2021a, b, c, d).…”