Covid mutations that worry the world have been in the country for a month and it was now known

SUBSCRIBERS EXCLUSIVE

They are two new versions of Omicron, popularly known as “Hound of hell” and “Nightmare”. Scientists investigate the link with the rise in cases.

It is difficult to determine if the Change of trend that occurred in the last two weeks in the curve of covid infections registered in the country, with a consolidated increaseis linked to two new sublineages of Omicron that are worrying the world and, now it was learned, they were already present in Argentina for a long time. more than a month.

The latest national Epidemiological Bulletin, corresponding to week 46 (November 13 to 19), reports for the first time the detection of a case of highlights B.Q.1.1 and another of the sublineage XBB.1, detected in week 41 (9 to 15 October). That is, they are infections that occurred five weeks before to be informed.

In the successive Bulletins that were published between week 41 and 45 (the latter between November 6 and 12) the percentage predominance of the BA.4 and BA.5 subvariants of the Covid was repeatedly detailed, but nothing had been said, despite the time elapsed, of BQ1.1 and XBB. 1.

The characterization of the variants in Argentina has an admitted weakness in a footnote to the official document of week 46: “Due to the small number of samples analyzed in recent weeks, no conclusions can be established regarding the percentage distribution of SARS-CoV-2 variants in the weeks subsequent to EW 37”.

Although Argentina never stood out in the pandemic for its genomic surveillance, since mid-September ´this is even more deficient. And it happens despite the fact that the Malbrán Institute has state-of-the-art equipment acquired in January 2021 to perform massive genome sequencing of Covid samples, with the potential to provide an accurate, real-time map of circulating variants.

According to official data, there are few samples to sequence the Covid genome in Argentina. Photo: Luciano Thieberger

Now the cases are growing again in Argentina and especially in the City of Buenos Aires. The part of this Sunday corroborated that at the national level there was a 50 percent increase compared to the previous week. In Buenos Aires, meanwhile, the rise is increasingly pronounced: it was from 122 percentwhen seven days ago the interweekly variation had been 91 percent.

Going back to BQ1.1, it is the sublineage popularly called “Hellhound”, which the World Health Organization (WHO) does not admit with that name because it considers that it causes confusion. XBB.1, meanwhile, has been baptized by the social imaginary “Nightmare”a nickname that has also been vetoed by the health agency.

The appearance of these new Covid mutations in the world generates uncertainty and concernbut the WHO has said that there is no concrete evidence that these new sublineages of the Omicron variant are more aggressive than the previous ones.

However, there are European, Asian and American reports that attribute to these versions of the virus the fact of having perfected its ability to infect and reinfect to those who had already contracted the disease with other early versions of Omicron.

As BQ1 descends from the subvariante BA.5 from Ómicron and has a greater presence in Europe and the United States, XBB.1 is a hybrid of two lineages of BA.2: BA.2.10.1 and BA.2.75, and has spread to a greater extent in Asia.

A key difference between BQ.1 and XBB is the number and location of mutations in the human receptor-binding domain, known as the Spike protein. This part of the protein is necessary for the virus to infect cells and is also the target of antibodies, which are an important part of the immune response.

The genomic sequencer that Malbrán bought in January 2021.

A recent study not yet peer-reviewed suggests that mutations within the receptor-binding domain may help XBB to escape neutralizing antibodies generated by previous Covid vaccines or infection with Omicrons, including BA.2 and BA.5 subvariants.

This scientific preprint considers XBB as one of the sublineages of the coronavirus more evasive of antibodies known so far. But the good news, according to data provided by Singapore, is that XBB reduced 30 percent the number of hospitalizations for Covid.

That would only confirm the logic that has been characterizing the evolution of Covid in recent times: a increasing agility to infect and replicate at the cost of resigning -vaccination through- a large part of its original power of damage.

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