Specialists look into the Mu variant of the coronavirus – Telam

The declaration by the World Health Organization (WHO) as a variant of “Mu” interest to the coronavirus lineage first identified in Colombia this week has sounded alarm bells in Latin America and, although the Delta continues to be the predominant and the most worrying one in the world, The specialists stressed that “we need to closely monitor Mu’s news and see how it interacts with others circulating in the country.”

“Right now, the Delta variant continues to be the one of greatest concern in the world; she was responsible for dramatic situations such as the health crisis in India; it has spread to hundreds of countries and has moved the circulating virus to where it entered. generate new waves “said Tlam virologist Humberto Debat.

Debat, who is part of the Argentinian inter-institutional genomics project SARS-CoV-2 (PAIS), recalled that “there is ample evidence that Delta is the most transmissible variant, doubles hospitalization rates, while vaccines are less effective in protecting us from contagion of this variant, although the levels of coverage in severe cases remain very high ”.

“Seeing that Mu represents 14% of cases in Chile to date, this implies that there is a probability that it will enter our country and increase its frequency”“

Humberto debate

However, he explained that you have to be aware of what is going on with the Mu “because, as we have seen in previous waves, the variant landscape at the Latin American level has had a big impact on Argentina.”

“Seeing that to date Mu represents 14% of cases in Chile (which had a scenario variant very similar to ours), implies that there is a probability that it will enter our country and increase its frequency “, Debate analysis.

On August 31, WHO published its weekly epidemiological update report in which it reported having incorporated as a variant of interest the B.1.621 line first identified in January in Colombia, which it designated by the letter Greek Mu.

“The Mu variant has a constellation of mutations that indicate potential immunological escape properties. The preliminary data presented to the working group on the evolution of the virus show a reduction in the neutralization capacity of convalescent and vaccinated sera similar to that observed for the Beta variant. (identified in May 2020 in South Africa), but this needs to be confirmed by further studies, ”the agency said in the document.

In this sense, Debat argued that what “said by the WHO, that the same organization indicated that this needs to be reconfirmed and is not yet in any scientific publication, is a big call for attention because Beta is the variant which presented the greatest immune evasion or evasion, that is to say for the one with the least coverage offered by the vaccines ”.

According to the WHO, “although the global prevalence of the Mu variant among sequenced cases has decreased and is currently less than 0.1%, the prevalence in Colombia (39%) and Ecuador (13%) has increased steadily ”.

“We also know that it represents 14% of cases in Chile, that is to say that during the last time, it started to spread in different countries of Latin America. and increase its frequency; this is not minor because the replication in other regions implies that it is independent of the conjuncture and therefore that it is a ‘property’ of the virus “, described the virologist.

“The Delta is the majority in the world and it has a better chance of entering it, but we will have to see how this relationship is established, which is dynamic”“

Josefina Campos

For its part, biochemist Josefina Campos, coordinator of the Anlis-Malbrn platform for genomics and bioinformaticsHe assured that “it is difficult to say which variant should cause the most concern in Argentina because the behavior of each will depend on many factors, including how it interacts with the variants that are circulating.”

“The Delta is the majority in the world and it has a better chance of entering it, but we will have to see how this relationship is established, which is dynamic”, aadi.

Regarding Mu, Campos indicated that there is still little data, but we know that it has become very widespread in Colombia and Ecuador, so “you have to keep in mind that what you are seeing is the footage information that you are sharing, but we do not know what it looks like the methodology of this surveillance. “

In principle, both in Colombia and Ecuador, “the delta is very low, but it would be hasty to say that this is the result of how they competed, we will have to wait a bit to see what happens when they live in the same territory. “

What variants circulate in Argentina

According to the latest report from the Ministry of Health on epidemiological surveillance in the country, carried out by the PAIS Project and the Anlis-Malbrn, the most common variant in Argentina is Gamma (defined as of concern by WHO and first identified in Manaus, Brazil) with a percentage close to 60% of the samples.

Lambda follows (defined as interest and known as Andean) with about 20%; while the Alpha (UK) does not reach 10%.

“What is today the Mu variant was already detected in August in sporadic cases in the city of Buenos Aires, in some travelers and two or three unrelated cases; it was found as part of the systematic surveillance carried out in the city, ”said Mariana Viegas, researcher at Conicet and coordinator of the PAIS project.

The most common variant in Argentina is Gamma, identified for the first time in Manaus, with a percentage close to 60% of the samples.“

However, he stressed that to say that there is community circulation of a variant “it must be systematically detected over time and there must be a risk that the population acquires it in the community, which does not has not yet happened with Mu “.

For his part, Campos indicated that Malbrn had detected the line now called Mu in April and “had already observed the constellation of mutations which were of interest”.

The C.12 variant

Another news this week was the public announcement by health authorities of South Africa what were they followed by a new variant, “C.1.2”, which has not yet been classified by WHO.

“This is a variant that has a large number of mutations: only in the protein Spike it has more than 12 and in total it has about 59 mutations compared to Wuhan (China); so this is one of the versions of the virus most different from the reference one, but the good news is that you don’t see any distinctive epidemiological behavior, ”Debat described.

The specialist said that “So far, it does not extend geographically or chronologically” and that “worldwide only 101 samples have been reported”.

Finally, Campos recalled that “having the greatest amount of population with the two doses is what will allow us to better cope with the Delta variant in the event that it starts to have a majority community circulation”.

“Most vaccines have been shown to offer very good two-dose protection against Delta to prevent hospitalizations and death,” he concluded.