SARS-CoV-2 Variants and COVID-19: An Overview

‘In the struggle for survival, the fittest win out at the expense of their rivals as they succeed in adapting themselves best to their environment.’

Owing to their constant replicative cycle, all viruses, including coronaviruses, change over time. This leads to multiple progenies of viral strains, with virulence traits that are unlike those of their parents. Since the arrival of the parental strain of SARS-CoV-2 from China over a year ago, it too has followed the natural Darwinian pathway of ‘survival of the fittest,’ leading to the production of three major strains/variants, currently in global circulation. These, the UK (Kent), the South African, and the Brazilian variants, with different geographical origins and sharing some of the mutations, are highly transmissible and equally deadly. Whether the variants are vaccine resistant is yet another major concern. Here, we provide an overview of how viral variants emerge and the signs and symptoms of variant-related COVID-19. The elucidation of the similarities and differences between SARS-CoV-2 variants should be helpful in developing future strategies to combat the pandemic.