Jean-Michel Pawlotsky Head of department at Henri-Mondor hospital in Créteil (Val-de-Marne)
What mutated in the British and South African strains?
Jean-Michel Pawlotsky Mutations have been observed in the Spike protein (which allows the virus to enter our cells – Editor’s note). Other mutations have taken place, but which are of less interest to us because they are not involved in the attachment of the virus to cells, nor in the neutralizing response.
What do we know about the origin of these mutations?
Jean-Michel Pawlotsky That there are English, South African, Japanese variants… is not surprising. The emergence of mutations is part of the normal evolution of viruses. If they offer any advantage, a new strain of virus is taking over, which is what is happening in England. It is suspected that the British variant appeared in an immunocompromised patient. These people often have long infections and carry the virus for weeks or even months. This gives the virus the opportunity to mutate. In the case of the English variant, this has not yet been demonstrated with certainty, but it is the hypothesis that is today the most accepted.
Are mutant strains always intended to replace the original strain?
Jean-Michel Pawlotsky It’s a competition. Two populations develop and if one has a selective advantage over the other, it will gradually replace it. It is extremely likely that the English strain will replace the strain that we know today. We are therefore going to meet more and more cases of the English variant. It has been suggested that it is a virus that could be more contagious, which would be one explanation for its faster progression. But this does not change the disease, nor the means to fight against it. We know that it is a variant which does not induce a more severe disease. It can be more contagious, which can lead to having to tighten the health and prevention measures. But the two options we have remain the same as before: barrier and braking measures, and vaccination. The fact that it is a slightly different virus does not change the root of the problem.
Has the government taken too long to react?
Jean-Michel Pawlotsky If the English, who detected the variant in September 2020, had warned us at that time and not at the end of December, that would have been useful… We could have set up a more active search for this variant in our region. From the moment we received the information, we got down to business. At Henri-Mondor Hospital, we decided to sequence all of our positive samples. We found no carriers of the variant. But on other samples that were sent to us from other centers, we identified two cases. The national survey carried out on positive tests last Thursday and Friday should give us a more precise idea of the percentage of English variant in the positive population. We know he is present. Its proportion will increase, it is inevitable. But what is important is still knowing how many people are infected each day, to understand whether or not we are moving towards exponential progression and a third epidemic wave.