Skip to main content

Prevalence of SARS-CoV-2 variants in Italy (ISS Report n. 19 and April 4th 2022 ISS Flash Survey)

Prevalence of SARS-CoV-2 variants of concern in Italy (according to the 19th ISS genomic surveillance report and the ISS Flash Survey of April 4th 2022)

Published: 03 May 2022

The I-Co-Gen platform by the Italian National Institute of Health (ISS) is the most up to date system 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), supported by the Bruno Kessler Foundation and in collaboration with the Italian Ministry of Health, the Regional administrations and the Autonomous Provinces (PPAA), have launched a coordinated effort to monitor the spread of SARS-CoV-2 variants in Italy. Results 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 (data from April 4th 2022). Data from the previous report (data from March 7th 2022) are also included for the sake of comparison.
Prevalence of SARS-CoV-2 variants in Italy (ISS Report n. 19 and April 4th 2022 ISS Flash Survey)
The table reports the prevalence of the Delta (B.1.617.2 and derivative lineages AY.n) and Omicron (B.1.1.529 and derivative lineages AB.n) Variants of Concern (VOC) of SARS-CoV-2 in Italy. Additional information concerning the nomenclature standards and genomic 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 genome sequences included in the analysis is reported as well. Aggregated data are also reported to present an overview of the current situation in Italy.
Matched data from the previous report (March 7th 2022) are included.

According to the most recent Flash Survey (April 4th 2022) the Omicron variant (lineage B.1.1.529 and derivative lineages BA.n) is the only variant circulating in Italy with an estimated prevalence of 100,0% in every Region/PPAA. Interestingly however we witness a shift in the prevalence of the two main Omicron variant lineages: BA.1 and BA.2. The latter, in fact, almost doubled its prevalence in Italy with respect to the previous update (March 7th 2022), increasing from 44,07% to 86,6% (regional range from 46,5% to 100,0%). At the same time the prevalence of BA.1 decreased significantly, from 55,78% (previous update) to 11,8%. These results are consistent with trends observed in several European and extra-European countries. Finally, it is worth mentioning that BA.1/BA.2 recombinant sequences were detected in Italy, in the context of the same Flash Survey. More specifically, the two recombinants identified were XJ (prevalence of 0,5%) and XL (prevalence of 0,9%). According to the World Health Organization (WHO) guidelines, these recombinant Omicron lineages should be monitored with particular attention, since at present the level of risk those variants might pose for public health (both in terms of transmission and severity of the disease) is still largely unknown.

Please refer to the reports 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)