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Prevalence of SARS-CoV-2 variants in Italy (ISS report n. 11)

Prevalence of SARS-CoV-2 variants of concern in Italy (adapted from the eleventh ISS genomic surveillance report)

Published: 22 November 2021

The I-Co-Gen platform developed by the Italian National Institute of Health (ISS), and released in April 2021, is currently the most up to date and reliable system for the analysis and collection of SARS-CoV-2 genomic sequences in Italy. Since its release the Italian National Institute of Health (ISS), supported by the Bruno Kessler Foundation and in collaboration with the Italian Ministry of Health, the Regional administrations and the Autonomous Provinces (PPAA), have started an ongoing and coordinated effort for the accurate mapping of the spread of SARS-CoV-2 variants in Italy based on the data incorporated in I-Co-Gen. Results are released periodically in the form of brief reports (further details here).
This highlight provides a brief overview of the main results presented in the most recent report (data updated to September 28th 2021). Data from the previous report (August 24th 2021) are also included to facilitate the comparison.
Prevalence of SARS-CoV-2 variants in Italy (ISS report n. 11)
The table reports the prevalence of the three Variants of Concern (VOCs) of SARS-CoV-2 currently recognized by international health authorities: Beta (B.1.351), Gamma (P.1) and Delta (B.1.617.2). Additional information concerning the nomenclature and features of these variants can be found here, in a paper by the World Health Organization (WHO).
Prevalence data are stratified by Region/Autonomous Province, the total number of genomic sequences included in the analysis is reported as well. Aggregated data are also reported to offer an overview of the current situation in Italy.
Matched data from the previous report are included for the sake of comparison (September 24th 2021).

According to the most recent ISS report (genomic data updated to September 28th 2021), all the isolates of SARS-CoV-2 sampled in our country belong to the Delta variant of the virus (lineage B.1.617.2 and derivative lineages AY.*). Consequently, the prevalence of the Delta variant is equal to 100% in all the Regions/PPAA and no cases of COVID-19 associated with other VOC (either Beta (B.1.351) or Gamma (P.1)) have been reported at this time.
Finally, following the September 3rd decision by ECDC to descale Alpha from the status of VOC (see link for more details), this variant is not included in the current report.

To obtain detailed information concerning the data included in the report, the methods applied and the technical limitations of the survey, please refer to the complete report as available on the ISS website at the following links (italian only):

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

Source: ISS (prevalence data)