CHAPTER 12: Significant SARS-CoV-2 Variants Circulating Around the World: Origin, Spread and Phylodynamics

Viruses pose an ever-present threat to mankind, as witnessed recently in the coronavirus disease 2019 pandemic caused by a divergent RNA virus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus has had a grave impact on the physical, mental and economical status of human beings by its own life-threatening etiology as well as by interrupting regular healthcare services, travel, commerce, education and many other societal sectors during the global lockdown. All viruses undergo evolution over time, which may or may not lead to an increase in infectivity or transmissibility in addition to resistance to drugs devised to parental/original strains. Thus, as expected, the SARS-CoV-2 virus has undergone mutation over time. In this chapter, we list all significant variants of SARS-CoV-2 reported to February 2021, with their respective mutations and epidemiological statistics. We believe that this compilation will help in the mapping of origin, spread and phylodynamics of the evolving SARS-CoV-2 virus, which may aid in constructing control policies.