Variant detected in South Africa: “Part of its mutations is associated with the contagiousness of the virus”

Will the next wave be that of the B.1.1.259 variant, also called “Nu”? While the Delta variant is present in more than 90% of the genomes of the Covid-19 virus, a new version of SARS-CoV-2 was identified in South Africa on Thursday. Presenting no less than 32 mutations on the Spike protein, this variant makes scientists fear a reduced efficacy of vaccines.

Cases have since been discovered in Botswana, Hong Kong, Israel, and possibly Belgium, adds Professor Antoine Flahault on LCI. This Friday, several countries including France suspended their flights from Central Africa. Should we then be worried? We talk about it with Vincent Maréchal, professor of virology at the University of the Sorbonne in Paris.

What do we know about this new South African variant?

For the moment, we only have fragmented information. Official sources tell us about 22 cases, the review Nature mentions 77 positive samples, but not much more is known. We know, however, that it has around thirty mutations which can occur in the Spike protein, this protein targeted by vaccines. Some of these mutations are associated in particular with an immune escape (resistance to the vaccine, editor’s note) and the contagiousness of the virus, which may be worrying, but we do not yet know the real impact of these mutations. What are their roles ? We are still awaiting a scientific response.

Is this worrying?

This is neither good nor bad news. It’s an alert that must be watched. Just be careful not to say to yourself: “It does not matter if the virus is circulating, as long as I am not sick”, because with these behaviors, we risk increasing the chances that a variant of this type emerges. Now, epidemiologists must also join in the dance. We must monitor the dynamics of this new variant: where is it? Who is contaminated and how quickly does it infect? We must quickly quantify and get out of speculation.

Why did it happen in South Africa?

South Africa is a special area, with a bit of a problematic characteristic. There, the population is very affected by the HIV virus, and has a much more fragile immunity than with us. As a result, South Africans are more susceptible to persistent infections like Covid-19 is. And as I said, the more a virus circulates, the greater the risk that an immune escape variant – less sensitive to vaccines – develops in a population. For the Delta variant – discovered in India – the environment was different: precautions to reverse the epidemic were almost non-existent while many political rallies were being held at that time. All these conditions have allowed an explosion of cases and therefore, the arrival of a different strain of Covid-19. However, as always in science, you only find what you are looking for. There may be other reasons, but we don’t know yet.