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Prevalence of SARS-CoV-2 variants in Italy (ISS Report n. 28 and January 10th 2023 ISS Flash Survey)

Prevalence of variants of concern of SARS-CoV-2 in Italy, according to the 28th genomic surveillance Report and the Flash Survey of January 10th 2023 by ISS (data published by ISS on February 3rd and January 20th 2023)

Published: 16 February 2023

The I-Co-Gen platform by the Italian National Institute of Health (ISS) is the reference point for the collection and analysis of SARS-CoV-2 genome sequencing data in Italy. By periodic analysis of the data processed through I-Co-Gen, the Italian National Institute of Health (ISS), in collaboration with the Bruno Kessler Foundation and with the Italian Ministry of Health, the Regional administrations and the Autonomous Provinces (PPAA), have undertaken a coordinated effort to monitor the spread of SARS-CoV-2 variants in Italy. Data are released periodically in the form of brief reports (further details here, Italian only).
This highlight provides a brief overview of the main results from the most recent report (January 10th 2023). Data from the previous report (December 13th 2022) are also included for the sake of comparison.
Prevalence of SARS-CoV-2 variants in Italy (ISS Report n. 28 and January 10th 2023 ISS Flash Survey)
The table reports the prevalence of the Omicron (B.1.1.529, derivative lineages and recombinant lineages) Variant of Concern (VOC) of SARS-CoV-2 in Italy. Additional information concerning the nomenclature and genomic features of this and other variants can be found here, in a paper by the World Health Organization (WHO).
Data are aggregated by Region/Autonomous Province and the total number of genome sequences considered in the analysis is reported as well. Cumulative data are also reported to present an overview of the current situation in Italy.
Matched data from the previous report (December 13th 2022) are included.

According to the results of the January 10th 2023 Flash Survey by ISS, the Omicron variant (B.1.1.529, its derivative lineages and recombinant lineages) is the most prevalent variant in Italy and its prevalence at National level is 100,0%.
Among Omicron sublineages BA.5 is the most widespread. In fact, BA.5 prevalence equals to 86,3% (slight decrease with respect to the 90,6% of the previous update) and it is above 74,0% in all the Regions/PPAA that took part in the Survey. Furthermore, according to Report n. 28, the proportion of BA.5 sequences assigned to the BQ.1.n sublineage is also increasing (going from 57,9% in December 2022 to 65,0% in January 2023). Among them BQ.1.1 is the most prevalent (frequency increasing from 30,8% to 38,9%).
The prevalence of BA.2 lineage increased from the 6,2% of December 13th 2022 to the 9,8% of January 10th 2023. Moreover, the number of sequences assigned to the CH.1.1 lineage, a derivative of BA.2.75 which is currently under international monitoring, is also increasing (from 0,62% to 2,25%, Report n. 28).
A slight increase (from 3,0% to 3,6%) in the prevalence of Omicron/Omicron recombinants is observed. According to the most recent Report by ISS the prevalence of XBB.1.5 (a recombinant of BJ.1 and BA.2.75 with an additional F486P Spike mutation) is increasing particularly (from 0,05% to 1,08%) and it’s under monitoring.
Finally, the prevalence of BA.4 is stable (0,3%).

Please refer to the report as provided on the ISS website at the following links (italian only) for a complete reference:

The previous report is available at the following link (italian only):

Source: ISS (prevalence data)