**6. Conclusion**

SARS-CoV-2 first appeared in late 2019 in Wuhan, China, as a positive-sense, single-stranded RNA virus with crown-like S-shaped spiking proteins; and has since spread throughout the world, resulting in a global pandemic of acute respiratory illness in people of all ages, with symptoms ranging from mild to fatal. It can undergo mutations, creating a lineage of virus progeny. It has become a continuously evolving disease due to rapid changes in the viral variants. They differ from each other due to one or more mutations, such as the number and location of substitutions in the S protein that makes each unique. This article discusses the genetic lineages of SARS-CoV-2 that have emerged as variants and circulated globally during the two years since the onset of the COVID-19 pandemic. There are four classifications by SIG of which the most alarming is classified as VOC. Important VOCs are Alpha, Beta, Gamma, Delta, and Omicron. Some of the lineages of these mutations are N501Y, D614G, N439K, Y453F, and others, which are globally dominated by clades 20A, 20B, and 20C. Of these, Alpha was the earliest and most infective initially. Variants have mostly emerged from countries like the United Kingdom, South Africa, Brazil, and India. The mutations are thought to appear due to massive human-to-human transmission, which is why prevalence is particularly higher among unimmunized persons. Other classifications are defined as VBM, VOI, VOC, and VOHC but most of these are at lower risk for infectivity, although they are still being monitored for new data. To date, no SARS-CoV-2 variants are designated as VOI or VOHC. Of note, further research is required to fully understand these variants and increase the accuracy of treatments. The public should consider vaccination along with preventative measures, such as wearing a mask, washing hands frequently, and practicing social distancing for the best chance of avoiding contact and increase in the variants.
