Vol. 4, Issue 1, Part A (2022)

On 26 November 2021, WHO designated the variant B.1.1.529 a variant of concern (VOC), following advice from the WHO’s Technical Advisory Group on Virus Evolution. The variant has been given the name Omicron. Omicron is a highly divergent variant with a high number of mutations, including 26-32 mutations in the spike protein, some of which may be associated with humoral immune escape potential and higher transmissibility. The current global epidemiology of SARS-CoV-2 is characterized by the global dominance of the Omicron variant. All other variants, including variants of concerns (Alpha, Beta, Gamma and Delta) and variants of interest (Lambda and Mu) continue to decline in all six WHO regions. Among the 432 470 sequences uploaded to global Initiative on Sharing All Influenza Data (GISAID) with specimens collected in the last 30 days, 425 227 (98.3%) were Omicron, 7 191 (1.7%) were Delta and one (<0.1%) was Lambda. During this same period, there was no Alpha, Beta, Gamma or Mu sequences reported. The purpose of this review was to summarize the structural characteristics, epidemiology of the Omicron variant and its potential to evade the immune response.