“The Delta variant (B.1.617.2) has a relative frequency of 100% in the week of 9-15 August in all regions, according to data collected to date”, states the INSA report on diversity genetics of the virus that causes covid-19.

According to the institute's data, of the total analysed sequences of this variant, 66 had an additional mutation in the `spike' protein, a sublineage known as Delta Plus that has “maintained a relative frequency below 1%” in recent weeks.

According to the INSA, the prevalence of Beta and Gamma variants, originating in South Africa and Brazil, respectively, remains low and without a growing trend.

With regard to the Alpha variant, associated with the United Kingdom and which was once predominant in Portugal, it was not detected in Portugal in the week of August 9th to 15th, after having been responsible for almost half of the cases of infections by the new coronavirus in the week between May 31st and June 6th.

As part of this continuous monitoring of the genetic diversity of SARS-CoV-2, approximately 565 sequences have been analysed weekly since the beginning of June, from samples collected at random in laboratories distributed throughout the 18 districts of mainland Portugal and the autonomous regions of the Azores and Madeira, covering an average of 121 municipalities per week.

In June, the institute announced a strengthening of surveillance of the variants of the virus that causes covid-19 in circulation in Portugal, through its continuous monitoring.

According to the INSA, this strategy allows for a better genetic characterization of SARS-CoV-2, since the data will be analysed continuously, and there will no longer be time intervals between analyses, which were essentially dedicated to specific genetic characterization studies requested by the public health.