The genomic and clinical features of the COVID-19 Omicron variant: a narrative review

Abstract

Coronavirus disease 2019 (COVID-19) is a major cause of morbidity and mortality worldwide. Since late November 2021, the Omicron variant has emerged as the primary cause of COVID-19 and caused a huge increase in the reported incidence around the world. To date, 32-34 spike mutations have been reported to be present in the Omicron variant, 15 of which were located in the receptor-binding domain that interacts with the cell surface of the host cells, while the rest were located in the N-terminal domain and around the furin cleavage site. Recent studies have suggested that those mutations could have a major role in the transmissibility and pathogenicity of the Omicron variant. Additionally, some mutations might contribute to the change of viral tropism of this novel variant. Here, we aim to discuss the recent reports on the transmissibility and severity of the Omicron variant from both the genetic and clinical perspectives. Afterward, we also take the chance to deliver our personal view on the topic.

Microbiological and Clinical Findings of SARS-CoV-2 Infection after 2 Years of Pandemic: From Lung to Gut Microbiota

“…However, the spreading of new VOCs, such as omicron, determined different clinical conditions involving mainly the upper respiratory tract [ 30 ]. This could be related to specific mutations that cause a modification in the viral interaction sites prevalently located in the upper airways [ 31 ]. In fact, some studies show how the omicron variant mainly replicates more rapidly in the bronchi than in the lung parenchyma [ 32 ] and how it replicates less in the lower airway tract compared to the delta variant [ 33 ].…”