“We don’t create panic. The most cunning are the unknown strains that turn into those who have no defenses »- Corriere.it

“We should not be afraid to recombine viruses belonging to sub-variants of the same strain, as is the case with a virus called Xe,” reassures the virologist Giorgio Palohead of the Italian Medicines Agency Aifa.

So where can the real threats come from?

“A new variant that has acquired unknown mutations, replicates in individuals with compromised immune systems, such as immunosuppressed patients. By becoming infected, these people host the virus in their bodies for several months, failing to eliminate it. Under Under these conditions, the SARS-CoV-2 virus can change and create a new predicament.”

So the warnings about recombination should not be taken lightly?

“They should stay in control but without too many mental worries. It’s genetic exchanges of two Omicron sub variants, BA1 and BA2, that infect the same cell and exchange gene segments to create a new virus, not as dangerous as our immune system recognizes it. I would note that recombination is done in healthy subjects, who may have already been vaccinated. And that the recombinant viruses are 99% identical to the Omicron variant circulating in the circulation, which is characterized by a very high infection index, equal to that of the measles virus.”

Let’s start from the beginning. What is recombinant?

“It is the result of material exchange between identical parts that are part of the same gene belonging to the genomes of two viruses that infected the same cell simultaneously. Genetic recombination particularly affects double-stranded DNA viruses. Among the RNA viruses are retroviruses (viruses responsible for AIDS and some types of human cancer) and retroviruses, to which the SARS-CoV-2 virus belongs to the family».

Are they frequent “surprises”?

“The recombination event is common in coronaviruses because they are the most widespread viruses in nature and have an extended genome, consisting of 30,000 letters and 30 genes. Let’s imagine the number of different clusters that can arise from two different viruses that intersect with each other.”

What significance should be ascribed to the recombinant sequencing in the laboratory of Asp of Reggio Calabria, renamed Xj?

“It is also not surprising because, according to the testimony of the Higher Institute of Health, a variant has already been identified as Xe in the UK, where sequencing activity is very intense and where Omicron sub-variants, compared to other countries, circulated earlier and more widely.”

The European Ecdc monitors all of these differences. What has he indexed so far?

“The agency is monitoring Xe along with the Xd and Xf recombinants, resulting from the genetic exchange between Omicron and Delta variants. In the UK they have found at least 700 cases of recombinant Xe. Let’s see if it increases. For now there is no need to worry.”

What did your British colleagues notice?

Xe is a recombinant of Sars-CoV-2 in the spike protein gene and has three other mutations in genes encoding non-structural proteins. At the present time, there are no data showing whether this recombinant has greater infectivity or virulence characteristics than the now prevalent BA2 sub variant.”

Are symptoms of infection due to recombinant not a cause for concern?

«No, on the contrary, all clinical manifestations seem to be characterized by minor symptoms. It should be noted that Xe is not the first example of a recombinant virus identified during the Covid-19 pandemic. Many of these recombinant viruses had already appeared in the context of previous variants (Alpha, Beta, Gamma, Delta) and subsequently became extinct without a trace.”