Research Progress in Taxonomy of SARS-Cov-2 Variant Strains

• 1、Public Health School, Harbin Medical University, Harbin, 150081

Abstract：Coronavirus is a group of enveloped single positive-stranded RNA viruses, divided into 4 genera and 45 species. Both the SARS-Cov-2 and the SARS-Cov virus belong to the SARS species of the beta coronavirus genus. Since the outbreak of the COVID-19 at the end of 2019, a certain number of mutant strains have been discovered, and these mutant strains are highly similar to each other. In order to achieve a better description of the epidemic trend of COVID-19, a few academic organizations such as the WHO have designed different classification schemes to classify and name the SARS-Cov-2 variant strains. According to the level of viral prevalence, the WHO named 8 important SARS-Cov-2 variants with Greek letters, which are divided into two levels: VOCs and VOIs. The Pango organization established a systematic multi-level classification method for mutant strains based on the genomic evolutionary tree, and developed web tools to facilitate researchers to calculate the taxonomic status of newly isolated strains. The defining mutation sites of theses 8 variants are concentraResearch Progress in Taxonomy of SARS-Cov-2 Variant Strainsted on the spike protein and replicase, suggesting that during the evolution of the virus, it is facing selective pressure on the two directions of immune escape and enhancement of replication ability.

Keywords： MedicalMicrobiology SARS-Cov-2 Variant Taxonomy