Information on the Delta variant (former Indian variant) is still very vague. (Drawing) – Deepak Gupta / Hindustan Times / Shu / SIPA
- After announcing that the Indian variant as a whole was of concern, the WHO has just clarified that only one of its mutations was involved.
- The mutation could be resistant to vaccines, but so far there is no evidence as the majority of infected people in the UK were not vaccinated.
- For experts, more than the nature of the Indian variant, it is the country’s strategy and its vaccination coverage that will be decisive in the evolution of the pandemic.
A month and a half after his discovery we finally know very little about him. WHO has announced that it considers only one subline of the Indian variant, now called Delta, to be of concern. A small change compared to May 11, the date on which the organization considered the variant as a whole worrying.
This Tuesday’s announcement could therefore lead one to believe that after the appearance of this variant in India in mid-April and the enormous wave of contamination it has caused in the country, scientists are starting to tame it and better know. What do we really know about this variant at the moment?
Indian variant, Delta or B1.617?
At the beginning of the week, the one that until now was called the “Indian variant” changed its name. The WHO has indeed decided to rename all the variants by Greek letters, easier to pronounce and remember, but not only. “The global policy is not to call them by the name of a country because it is stigmatizing,” explains Martin Blachier, public health doctor and epidemiologist. We had somewhat regretted having given this name to the British variant. Its technical name, B.1.617, remains useful in particular to evoke its sub-lines. For the Delta variant, the B.1.617.2 subline is the one considered to be of concern, unlike B.1.617.3 for example.
What does it mean in concrete terms that a subline is “worrying”?
“It has become evident that more risks to the public are associated with B.1.617.2,” the WHO said during its weekly epidemiological update on the pandemic. Nothing very concrete in this statement. But for Martin Blachier, “there were so many unpleasant surprises that now politicians are covering themselves up and speaking extremely cautiously.”
Moreover, as the doctor Benjamin Davido explained to us in April, the situation in European countries should not be superimposed on others, because just like the Brazilian and South African variants, the Indian variant comes from a country where the situation health is less well managed, making it difficult to interpret the severity of it. “India is a country with different conditions of hygiene and access to healthcare [de celles que nous connaissons en Europe], with a high population density, and a country known to be a reservoir of infectious diseases, ”explained the doctor, therefore calling for caution. What happened in India therefore has nothing to do with what is happening today in the United Kingdom, where the number of cases of contamination linked to the Delta variant has increased. “The country is in the process of deconfining itself. They relax 100% of their barrier measures. There is a little more contamination but there is no peak, ”adds Martin Blachier. The day before, the United Kingdom, for example, recorded no deaths from the Coronavirus, for the first time since July 2020.
Is it resistant to vaccines?
“We say that it is worrying because potentially this mutation could be associated with a poorer sensitivity of vaccines”, explains the epidemiologist but for the moment this hypothesis is not verified. “All variants have mutations in common that they share. But it is not because we find the same mutations between the different variants that we can draw conclusions. “
“The only data we have on the effectiveness of vaccines are studies carried out at the Pasteur Institute in Paris on antibodies. We take the antibodies from vaccinated people, we put them with the variant in a tube and we see if the antibodies bind well to the virus and neutralize it. The problem is that immunity, whether vaccine or natural, goes through antibodies, but there is also cellular immunity which is not verifiable in the tube. Currently we do not yet have real data on vaccinated people who would still be infected with this variant. “
The epidemiologist points out that in the United Kingdom, for example, cases of contamination with the Delta variant “mainly concern Indian communities which were not vaccinated and which have potentially had contact with India”.
Is it transmitted more?
In view of what has happened in India and the rise in cases of this variant in some fifty other countries, the question arises. But here again, Martin Blachier calls for caution when interpreting data. “The moment one variant dominates the other variants, it is said to be more transmissible. It is not that we observed that the Delta variant created contaminations and waves, but it is simply that we realized that for example in Great Britain, the Indian variant was becoming the majority, so we says it is more transmissible. “
The variant in itself, less determinant than thea country’s strategy?
However, it is not necessarily on the strain of the virus that it is necessary to focus. “What is decisive is the strategy, the vaccination rate and also the vaccine used. The two RNA vaccines have higher efficacy rates, in particular on transmission, although in severe cases they are all very effective. This summer, like last year with the summer coverage, we will experience a lull in the spread of the virus. The real question is what will happen in September and October. This is where the strategies to be put in place must be reflected. Whatever variant we have at the start of the school year, it is the way in which we have vaccinated that will be decisive. And if we crash it will not be because of a variant but of poor vaccination coverage. “