A genetic mutation of SARS-CoV-2 has been spreading rapidly in Europe since this summer. It is the result of a super spreader event in Spain. It has spread through tourists and is now the predominant strain in most countries with a strong second wave.
Could the second wave of coronavirus in Europe this fall have been avoided? This is the hypothesis presented by researchers at the University of Basel, whose work has been pre-published on the MedXriv website. They discovered a variant of SARS-CoV-2 called 20A.EU1, which appeared in Spain at the end of June. Then it spread rapidly throughout Europe, leading to six more derivative variants with slight mutations. Practically non-existent at the beginning of July, this strain now affects 80% of cases in Spain and the United Kingdom, 60% of cases in Ireland, and 40% in Switzerland and France. In total, the 20A.EU1 strain has spread to 12 European countries including Belgium, Norway, and Germany, and has even been transferred as far as New Zealand and Hong Kong. It seems to be on the right track to overcome all other variants of SARS-Cov-2.
Mutations occur in all viruses, but most of them disappear quickly or remain rare. Only a few variants, like 20A.EU1, can emerge. It is difficult to determine which mutations affect the lethality of the virus. If the mutation is located in the higher protein with which the virus enters the body, it is possible that the mutation influences the virus’ behavior.
Another mutation in SARS-Cov-2, called D614G, also spread in Europe and the United States during the summer. Researchers believe that this change makes the virus more infectious but less dangerous, which may explain in part the lower mortality observed at the beginning of the second wave.
A single super-spreader event that has contaminated the whole of Europe
This new strain, which first emerged in June among agricultural workers in northeastern Spain, spread first among the local population, then through a super spreader event, it spread rapidly throughout the country and across borders. Tourists in Spain then facilitated the spread of the virus by adopting risky attitudes, such as ignoring the rules of social distancing and maintaining “this kind of behavior at home,” explain the researchers.
“I have never observed a variant of the virus with such a strong dynamic”
The central question remains whether this new strain is more infectious or deadly. “We have no evidence that this mutation increases transmission or affects clinical outcomes,” says a cautious Emma Hodcroft, a specialist in the genetic evolution of viruses at the University of Basel and principal author of the study. But she points out that 20A.EU1 is different from anything she has ever encountered before. “I haven’t seen a variant with such a strong dynamic since I started studying the genome sequences of coronaviruses in Europe,” she says.