From December 28, 2020 to May 19, 2021, the so-called English variant (lineage B.1.1.7) was identified in 73.06% of covid cases in Italy and the Brazilian variant in 6% (P.1). The prevalence of other variants of public health interest is instead less than 1% in our country, with the exception of the so-called Nigerian variant (1.17%). This is what is reported in the bulletin on “Prevalence and distribution of variants of the Sars-CoV-2 virus of interest for public health in Italy”, published online today by the Higher Institute of Health (Iss). The bulletin will be published every fortnight, while next Friday – the ISS recalls – the next rapid survey will be presented. The report integrates data on variants from the most recent rapid prevalence survey (flash survey) conducted by the ISS in collaboration with the Bruno Kessler Foundation, Ministry of Health, Regions and Autonomous Provinces. And it refers to a total of 23,170 cases of SarS-CoV-2 infection reported from 28 December 2020 to 19 May 2021 to the Covid-19 Integrated Surveillance System with genotyping by sequencing out of a total of 2,083,674 cases reported (equal therefore to 1.11%). “Although the trend of cases of confirmed infection – reads the Report – reported to the Covid-19 integrated surveillance system for which genotyping has been carried out or not is strongly influenced by the percentage of genotyped samples, which increases during rapid investigations of prevalence, a substantial stability is observed, with weekly fluctuations, in the number of genotypes reported and attributable to viral variants of health interest starting from the first week of February 2021, since the data collection system became fully operational “. “It is necessary to continue to monitor with great attention the circulation of variants of the Sars-CoV-2 virus – reads the report – and in particular the presence of mutations attributable to greater transmissibility and / or associated with a potential immune escape”.