Genetic and structural analyses reveal the low potential of the SARS‐CoV‐2 EG.5 variant

• Published in: Journal of medical virology 2023-09, Vol.95 (9), p.e29075-e29075
• Main Authors: Scarpa, Fabio, Pascarella, Stefano, Ciccozzi, Alessandra, Giovanetti, Marta, Azzena, Ilenia, Locci, Chiara, Casu, Marco, Fiori, Pier Luigi, Quaranta, Miriana, Cella, Eleonora, Sanna, Daria, Ciccozzi, Massimo
• Format: Article
• Language: English
• Subjects: Coronaviruses; Genetic analysis; Genetic drift; Genetic variability; Genomes; Monitoring; Population number; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Viral diseases; Virology; Viruses
• ISSN: 0146-6615; 1096-9071
• DOI: 10.1002/jmv.29075

The severe acute respiratory syndrome coronavirus 2 EG.5 lineage is the latest variant under monitoring, and it is generating significant concern due to its recent upward trend in prevalence. Our aim was to gain insights into this emerging lineage and offer insights into its actual level of threat. Both genetic and structural data indicate that this novel variant presently lacks substantial evidence of having a high capacity for widespread transmission. Their viral population sizes expanded following a very mild curve and peaked several months after the earliest detected sample. Currently, neither the viral population size of EG.5 nor that of its first descendant is increasing. The genetic variability appear to be flattened, as evidenced by its relatively modest evolutionary rate (9.05 × 10 −4 subs/site/year). As has been observed with numerous prior variants, attributes that might theoretically provide advantages seem to stem from genetic drift, enabling the virus to continually adjust to its host, albeit without a clear association with enhanced dangerousness. These findings further underscore the necessity for ongoing genome‐based monitoring, ensuring preparedness and a well‐documented understanding of the unfolding situation.