Waves and variants of SARS-CoV-2: understanding the causes and effect of the COVID-19 catastrophe.

The coronavirus disease-19 has left a permanent mark on the history of the human race. Severe acute respiratory syndrome coronavirus-2 is a positive-sense single-stranded RNA virus, first reported in Wuhan, China, in December 2019 and from there took over the world. Being highly susceptible to mutations, the virus's numerous variants started to appear, and some were more lethal and infectious than the parent. The effectiveness of the vaccine is also affected severely against the new variant. In this study, the infectious mechanism of the coronavirus is explained with a focus on different variants and their respective mutations, which play a critical role in the increased transmissibility, infectivity, and immune escape of the virus. As India has already faced the second wave of the pandemic, the future outlook on the likeliness of a third wave with respect to the Indian variants such as kappa, delta, and Delta Plus is also discussed. This review article aims to reflect the catastrophe of the variants of SARS-CoV-2 and the possibility of developing even more severe variants in the near future.

Evolutionary Dynamics of the Emergent SARS-Cov-2 Variants: Just Within a Year of Circulation

The emergence of newer SARS-CoV-2 variants recently reported in the UK, South Africa, and Brazil is a matter of great concern. The mutations mainly in the spike protein are the culprit behind the sudden rise in the infectivity and transmission of these variants. The scientific efforts provided us with few effective vaccines like Pfizer and Moderna, however the same needs to be re-investigated in the SARS-CoV-2 variants infected patients. This brief review, focuses on the emergence, how the variants originated and are geographically distributed around the world, which will make the researcher aware of the current pandemic situation