From Alpha to Omicron: How Different Variants of Concern of the SARS-Coronavirus-2 Impacted the World

SIMPLE SUMMARY: This review article comprehensively discussed the evolution of the SARS-CoV-2 virus since its initial outbreak in 2019. Specifically, we have provided insights into the genetic mutations and the emergence of different variants of concern and their classifications. We have emphasized the properties of these variants, highlighting their increased transmissibility, virulence, and potential for immune evasion. Lastly, we have provided a glimpse into the future perspective of the global health response and future variant prediction models. ABSTRACT: SARS-CoV-2, the virus that causes COVID-19, is prone to mutations and the generation of genetic variants. Since its first outbreak in 2019, SARS-CoV-2 has continually evolved, resulting in the emergence of several lineages and variants of concern (VOC) that have gained more efficient transmission, severity, and immune evasion properties. The World Health Organization has given these variants names according to the letters of the Greek Alphabet, starting with the Alpha (B.1.1.7) variant, which emerged in 2020, followed by the Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.1.529) variants. This review explores the genetic variation among different VOCs of SARS-CoV-2 and how the emergence of variants made a global impact on the pandemic.