Movements of the Sars-Cov-2 virus found in South Africa and Brazil have begun to worry authorities and scientists who say these could – they are different from the new variant first discovered in the UK – encouraging more re-infections, even reducing the effectiveness of vaccines. , although more experiments are underway.
The first major release of the Sars-Cov-2 virus from the UK was reported in the so-called B.1.1.7 version (also known as VOC202012 / 01); authorities said in December it was more contagious, and was seen as a factor in leading to the country’s worst wave yet.
Scientists also found a handful of other species that had been extensively translocated. Two of these, B.1.351, found in South Africa, and P.1 found in Brazil, are now likely to escape, at least in part, the immune response. in people who received the vaccine or had the disease earlier, preliminary studies and the government reports published this week say.
“These mutations and those that occur in people with underage or debilitated immunity may erode the effectiveness of natural immunity and immunization. The data indicate that Sars-CoV-2 vaccines may need to be updated, ”said a team led by researchers from Rockefeller University in a study submitted to Biorxiv on January 19.
Movements in virus are a natural phenomenon and the Sars-Cov-2 was seen to be gaining two important markers per month. But in December, researchers began to discover some series with an unusually high number of mutations – the UK-linked mast has 23 variants, the African-linked one has eight variants. South and the man has 20 attached to Brazil.
These changes include N501Y and E484K. These letters refer to how a particular portion of the virus has changed – these are essentially the changes in the Spike protein, the part that the virus uses to capture cells. Of these, N501Y has been linked to the virus being more infectious, and E484K is the modification that may make the virus more stable.
The UK variant carries the N501Y, the one seen in Brazil carries the E484K and the one seen in South Africa.
The researchers took these mutations for laboratory tests to find out how vaccine-induced immune cells responded to them. With plasma from 14 people receiving the Moderna vaccine and six people receiving the Pfizer-BioNTech dose, they saw a “small” but large drop in the way the immune cells neutralized the tribal rays compared to how the they neutralized the eldest.
Similar results were shared with the South African authorities on January 18. The B.1.351 variant (containing E484K) did not respond with antibodies in 21 out of 44 serum samples collected from South Africa. infected people in the first wave, South African scientist Salim Abdool Karim said at a debate broadcast online on 18 January.
There is also at least one confirmed case of relapse caused by the P1 version (which also has E484K). This was explained by Brazilian researchers in a study published on January 18, detailing the case of a 29-year-old woman in Manaus, Brazil, who developed a symptomatic disease in March. At the end of December, she became ill again with symptoms such as fever. Genetic sequences showed a second infection with the P1 mutation.
The Covid-19 Genomics UK consortium (COG-UK) said the emergence of such changes raises concerns that there could be an evolutionary co-occurrence that could spread the virus more quickly and harder to fight. “However, the effect of this booth on natural immunity or immunization has not yet been confirmed,” they said in a report published on January 19.
Researchers also say that the evolution of Sars-Cov-2 is not currently a major threat as the changes seen even so far do not produce existing immunity (from more advanced diseases). sine) or completely late vaccines.
It is linked to predictions that Covid-19 may be endemic, where it will be able to keep circulating by evolution but without leading to destructive effects. “The long-term effect of the accumulation of mutations on the Sars-CoV-2 on the pandemic is unknown, but the common cold coronavirus HCoV-229E induces antigenic changes that counteract the old but sensitive to contemporary sera, ”said the researchers in the first study.
In a study published in Science on Jan. 12, a team led by researchers from Emory University used transmission modeling and immunity frequency estimates to recommend, once Sars-Cov-2 a ‘endemic growth, that it resembles a common cold because childhood diseases provide protection against a later serious disease.