Coronavirus, epsilon variant could be more resistant to antibodies


Emerged in California and still not very widespread in Europe, epsilon appears to be more resistant to antibodies, even those induced by the vaccine. Fundamentals of sequencing and tracking

Photo: Fusion Medical Animation | Unsplash

I know delta, at the moment, it is there variant di Sars-Cov-2 which raises more concern, from California emerges one that must be kept under control: B.1.427 / B.1.429, called epsilon, according to the classification of the World Health Organization (WHO). At the moment still not very common in Europe, the variant owns three mutations borne by proteina Spike, that would make it more resistant to antibodies, and those deriving from the vaccination a messenger Rna, and those generated as a result ofinfection with the coronavirus. This is what emerges from the study conducted by researchers at the University of Washington in Seattle, led by biochemist Matthew McCallum: the results were published in the journal Science.

The two strains of Sars-Cov-2 named B.1.427 and B.1.429 are part of the epsilon variant, both identified in California, in the United States, between the end of 2020 and the beginning of 2021. The variant presents three different mutations inside the glicoproteina spike, the “access key” that allows Sars-Cov-2 to penetrate human cells, as well as vaccine targets and other experimental therapies against Covid-19, such as monoclonal antibodies. Precisely because the Spike protein plays a vital role in regulate immunity against the coronavirus, the researchers wanted to ascertain the possible changes induced by Epsilon, and how it could impact the future epidemiological situation.

What the study says

The in vitro study quantified theneutralization activity of human plasma from patients vaccinated or recovering from an infection of the original Sars-Cov-2 strain, against the epsilon variant. The antibodies against the spike protein should induce, in the presence of the coronavirus, the phenomenon of neutralization, i.e. physical blockage by antibodies of virus transmission in cells: when it occurs, this phenomenon is a good index of protection against virus infection.

Research was based on plasma analysis of 57 samples, resulting from 15 people vaccinated with two doses of Moderna, 33 vaccinated with two doses of Pfizer-BioNtech and from 9 recovering from Covid-19. Antibody neutralization data indicate, with the epsilon variant, a decrease equal to 2-3.5 times compared to the original coronavirus infection. This would indicate a greater resistance by epsilon both to antibodies generated by messenger RNA vaccines and to those generated by Sars-CoV-2 infection.

Sequencing is important

According to the database Gisaid, which traces the diffusion of the different variations of Sars-Cov-2 in the world, epsilon in the past four weeks has spread from the United States to others 44 countries. In Europe they are counted less than 100 cases, of which two in Italy. On 1 July 2021 theWHO and the European Center for Disease Prevention and Control (Ecdc) still designate epsilon among the “variants of interest“, Or those variants for which data are available that could significantly affect the transmissibility of the virus, the severity of the disease or the effects on immunity, with a realistic impact on the epidemiological situation.

Evidence that however, with respect to the “variants of concern”, such as the variant delta, I’m preliminary and to be ascertained, along with a continuous tracking of the genetic sequences of spreading coronaviruses. “Understanding the novel immune evasion mechanism of emerging variants – write the authors of the study – it is as important as monitoring the sequence itself to successfully counter the ongoing pandemic”.


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