Abstract:

Viruses undergo mutations over time, and sometimes these changes do not have any significant impact on the virus's properties. However, certain mutations can alter the way the virus interacts with the host's major components, leading to modifications in the host's machinery within the cell. These modifications can affect the virus's properties, such as its transmissibility, severity of the disease, effectiveness of therapeutic medications, vaccines, and other social and public measures related to health. This review paper aims to discuss the different variants of SARS-CoV-2 that have emerged since the first documented case of the virus. We searched for keywords such as severe acute respiratory syndrome coronavirus 2 and variants on websites like the World Health Organization and databases like PubMed, Medline, and blogs. We examined these sources to find relevant materials published on the topic. The variants are classified based on ancestry and segment mutations, and they are grouped into distinct categories based on their potential for causing severe disease. The identification of five notable variants since December 2020, namely the Alpha, Beta, Gamma, Delta, and Omicron variants, has blown up the virus lineages. These variants have added complexity to COVID-19 research and have required extra epidemiological, laboratory, and clinical research avenues.