Omicron BA.2 lineage frequency has increased in Portugal
The frequency of the BA.2 lineage of the omicron variant of the SARS-CoV-2 coronavirus has increased in Portugal and has a greater circulation in the North, Algarve and Lisbon and Tagus Valley, announced this Tuesday, the INSA.
“In Portugal, the BA.2 lineage was detected for the first time in random sequencing samples from week 27 December 2021 to 2 January 2022. Its relative frequency has gradually increased since then, reaching about 3% in week of January 24th to 30th”, see the report by the National Institute of Health Doutor Ricardo Jorge (INSA) on the genetic diversity of the coronavirus that causes covid-19.
According to the INSA document, this BA.2 lineage, which shares genetic characteristics with BA.1, has greater circulation in the North, Algarve and Lisbon and Tagus Valley regions.
The ómicron variant lines – BA.1 and BA.2 – descend from the same lineage of two ancestors designated as B.1 line1.529 and have an “excess” of the `spike´ protein, many of which are separate”, description of INSA.
As for the report, it states that, according to the sequencing data, its frequency has remained above 90% from the year to BA.1 since the beginning of the week of January 24th to 30th.
However, the updated data show an increasing trend of BA.1 in the week (87.4% on February 6th), “probably related to the circulation of the BA.2 lineage”, advances the INSA.
Recently, the director general of the World Health Organization, Tedros Adhanom Ghebreye, said that experts are following the evolution of several lineages of the omicron, including BA2.
Also on the same occasion, a WHO official for a pandemic said that this lineage of the omicron variant is registering an increasing circulation in countries such as Denmark and India, that the available data on its transmissibility and severity are scarce.
“We have good surveillance worldwide to understand the subvariants of the omicron. We are working with specialists from all over the world to study this virus and the strains, including BA.2, to better understand the changes”, assured epidemi Maria Van Kerkhove.
As part of the continuous monitoring of the diversity of SARS-CoV-2 that the INSA is operating, there were 54 sequences from an average of 2021 to the beginning of 2021, from a selection randomly selected in 18 labor districts of mainland Portugal and the Azores and Madeira, covering an average of 133 municipalities per week.