Prevalence of variants of concern of SARS-CoV-2 in Italy, according to the 25th ISS genomic surveillance report and the ISS Flash Survey of October 4th 2022
Published: 02 December 2022
This highlight provides a brief overview of the main results from the most recent report (October 4th 2022). Data from the previous report (September 6th 2022) are also included for the sake of comparison.
According to data collected during the October 4th Flash Survey performed by ISS, the Omicron variant (B.1.1.529, its derivative lineages BA.n and recombinant lineages) remains the only SARS-CoV-2 variant currently circulating in Italy, with an estimated prevalence of 100,0% at National level.
BA.5 is the most prevalent among Omicron sublineages as its prevalence equals to 93,01% on Italian territory and is above 75,0% in every Region/PPAA analysed.
Moreover, a slight increase in the prevalence of BA.2 from 1,11% in the previous update (genomic data from September 6th 2022) to 2,33% in the current update (genomic data from October 4th 2022) is observed. In particular we witness an increase in the number of genomic sequences assigned to BA.2.75 (and sublineages). This Omicron sublineage is under international monitoring as it presents mutations that could increase immune escape ability and increase ACE2 affinity [1,2].
Finally, no significant variation in the prevalence of BA.4, which is equal to 4,27%, is observed.
Please refer to the report as provided on the ISS website at the following links (italian only) for a complete reference:
- Report n. 25
- Prevalence analysis (October 4th 2022)
The previous report is available at the following link (italian only):
- Report n. 24
- Prevalence analysis (September 6th 2022)
Sources:
ISS (prevalence data),
[1] “Omicron sublineage BA.2.75.2 exhibits extensive escape from neutralising antibodies”. Daniel J. Sheward et al. November 2022,
[2] “Antigenic characterization of the SARS-CoV-2 Omicron subvariant BA.2.75”. QianWang et al. 9 November 2022