ID-19, which evolved from the SARS-CoV wild-type virus. Several novel variations developed during the COVID-19 pandemic, some of which are known as Variants of Concern (VOC). VOCs are classified as Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.1.529) by WHO [1]. These five SARS-CoV-2 VOCs have a substantial level of pathogenicity and transmissibility. New SARS-CoV-2 variants widely recognized as variations of interest (VOI) have been determined based on their transmissibility, severity of sickness, diagnostic escape, and immunological escape.In December 2019, the severe acute respiratory syndrome 2 (SARS-CoV-2) coronavirus outbreak began in Wuhan, China, and quickly spread to practically every corner of the globe, killing millions of people. SARS-CoV-2 produced numerous variants, five of which have been identified as variants of concern (VOC) by the World Health Organization (WHO) (Alpha, Beta, Gamma, Delta, and Omicron). We conducted a comparative epidemiological analysis of SARS-CoV-2 and its VOC in this paper. We compared the effects of vari-SUMMARY ous spike (S) protein mutations in SARS-CoV-2 and its VOC on transmissibility, illness severity, hospitalization risk, fatality rate, immunological evasion, and vaccine efficacy in this review. We also looked into the clinical characteristics of patients infected with SARS-CoV-2 and its VOC.