A “significant risk“reinfection and ineffectiveness of vaccines. This is what worries scientists about the South African variant of the coronavirus. Called 501Y.V2, this variant detected in South Africa in December 2020 is now present in 23 countries in Africa, Europe, Asia, Oceania, North and South America.
Its particularity is based on a mutation, called E484K. It acts on the Spike protein (or protein S), a surface protein that allows the virus to attach itself to target cells and enter them. Problem: the mutation seems capable of reducing the recognition of the virus by the antibodies, and therefore its neutralization by the immune system.
To read also: English, South African, Brazilian… what do we know about the new variants of the covid?
To better estimate this risk, South African researchers have confronted the 501Y.V2 variant in the laboratory with various blood plasmas from cured patients who had already been infected with the old variant of the virus. They detail their results in a preliminary study made public on January 19, 2021 on the site BioRxiv – but not yet evaluated by other scientists.
The plasma contains the “neutralizing” antibodies made during the first infection that are able to recognize and neutralize the virus. But according to the researchers, the new variant “is largely resistant to neutralizing antibodies“.
In other words, “most individuals infected with previous strains of SARS-CoV-2 will have minimal or undetectable neutralizing response against 501Y.V2“, worry the researchers. People already infected,”assumed to have acquired a certain level of immunity“could therefore not be protected against this new variant and declare a reinfection.
Are vaccines ineffective?
But that’s not all. This mutation could also have “implications for the efficacy of vaccines against SARS-CoV-2 since vaccines are mainly based on an immune response to the Spike protein“, insist the researchers.
They therefore underline the “urgent need“”identify targets“less prone to mutations and to develop platforms to adapt vaccines.
What the laboratories have promised to do, “in six weeks “, ensures for example BioNTech. If the results of the South African study are confirmed, a new schedule for the production and distribution of effective vaccines against 501Y.V2 should then be put in place.
“Not good news but not a surprise”
For the professor of biochemistry at the University of Oxford James Naismith, cited by the organization Science Media Center, “this is not good news but it is not a surprise “. According to him, “don’t panic “ but continue research.
Main objectives of this research to be carried out: “to evaluate the neutralizing power of the antibodies generated by the vaccination against the variants of the virus “ and “study the immune response of individuals infected with the variants“, suggests for his part the virologist Lawrence Young, of Warwick Medical School.
Same problem for the Brazilian variants?
Especially since the concern is not limited to the South African variant since the two Brazilian variants, including the one identified in Japan, also carry this E484K mutation.
This is not the case with the British variant, against which the Pfizer / BioNTech vaccine would be very effective, according to two preliminary studies published on January 20.