Viruses mutate over time, and these changes might have little to no effect on the property of the virus. Mutations that alter interactions with major host components might sway epigenetic regulation, which modifies and controls host machinery in the cell. Some modifications could affect the virus's properties, such as its transmissibility, disease severity, therapeutic medications, vaccines, or other social and public health measures. Since the first reported and documented case of SARS-CoV-2, mutations of the novel virus have led to different variants, which is the aim of this review paper. Keywords such as severe acute respiratory syndrome coronavirus 2 and variants were searched on the World Health Organization website and other databases such as PubMed, Medline and blogs. These sources were examined to identify and select relevant materials published. The grouping of variants is based on ancestry and segment mutations. Variants are placed into distinct categories based on the potential for causing severe disease. The identification of five notable variants since December 2020 has blown up the virus lineages. These variants: the Alpha, Beta, Gamma, Delta and the Omicron variant labelled as variants of concern, changed the face of the pandemic. These variants complicated the COVID-19 research plan and required extra epidemiological, laboratory and clinical research avenues.

Keywords: SARS-CoV-2, evolution, mutations, variants