Omicron: increased transmissibility and decreased pathogenicity

This is the authors' abstract. We don't add key points for this paper.

Three research papers were published recently to compare the virological properties of the Omicron variant with the earlier variants of concern (VOC). 1 , 2 , 3 The SARS-CoV-2 B.1.1.529 variant, Omicron, was first detected in South Africa in October 2021 and has spread rapidly; within three months, it appeared in more than 87 countries. 4 During the surveillance of the epidemiological data and mutations of earlier COVID-19 variants and Omicron, significant differences were revealed mainly in the reproduction rate and hospitalization. Although a modest severity can be observed in the case of Omicron, its 3,31-fold higher transmissibility 2 (Fig. 1d ) than Delta variant and increased resistance to antiviral immunity 1 represents a global epidemic threat. Fig. 1 Schematic presentation of main epidemiological and virological factors interdependences: a Omicron viral spike protein mutations and their consequences. b Altered cell entry pathway caused by higher binding affinity toward ACE2 receptors and lack of S1/S2 cleavage site. c Receptor distribution and expression in the respiratory tract cells. d Comparison of epidemiological and pathological properties of Delta and Omicron variants from Epidemiological data and in vivo hamster model Full size image