Origin and main features of gryphon, cerberus, kraken, orthrus, bythos, hyperion and arctur, the current SARS-CoV-2 variants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the most serious pandemics affecting the world in recent years. It was first isolated in China in 2019 and then spread and identified worldwide. To date, due to the numerous mutations accumulated on the viral genome, hundreds of virus variants have been isolated. As a general trend, the SARS-CoV-2 variants identified so far have increased their diffusion and reduced their danger and mortality. About 15 million viral sequences were carried out to control the spread of the virus and its variability. However, due to the reduced danger, from December 2022 to May 2023 a reduction was observed in the viral sequences collected and entered in the GISAID database (Global Initiative on Sharing Avian Influenza Data; https://gisaid.org) from 99950 to 25415 sequences, respectively. At the beginning of 2022, a new group of variants was isolated, referred to as omicron, which in a few months replaced all the variants present up to then. Here, we have examined the latest variants BQ.1, BQ.1.18 (CH.1.1), XBF, XBB, XBB.1.5, XBB.1.9 and XBB.1.16, indicating their origin and their derivation from the BA.2.12.1 and BA.5 variants, respectively, by analyzing the new mutations exhibiting these variants. Based on these studies, we proposed a new phylogenetic tree of omicron variants.