«It is possible that the Delta variant will also become dominant in Italy. But don’t be afraid although it is more contagious. The evolutionary process of a pandemic virus consists in adapting more and more to the host species and not in becoming more virulent, on pain of its own extinction. We will soon understand if we are dealing with a strain that gives rise to less severe manifestations targeting the upper respiratory tract, nose and pharynx ». The virologist Giorgio Palù, member of the Scientific Technical Committee and president of the AIFA board of directors, launches heartening messages “but do not forget the basic precautions, especially the use of a mask in crowded and closed places”.
How dangerous is the Delta variant?
“It is one of about 20 mutant Sars-CoV-2 strains considered a matter of concern. It appeared in December 2020 in a state in northern India, a few months later it was the cause of over 30 thousand cases a day in New Delhi, even among subjects already recovered and vaccinated ».
What new features does the Delta have?
“One of its three sub-variants has acquired mutations that make it 50% more infectious than Alfa (former English variant).”
Is it less bad, doesn’t it affect the bronchi and lungs?
“Some describe it as responsible for milder symptoms. Runny nose, headache. Typical of colds. We await more accurate studies. We do not know if this described minor aggression is linked to the fact that in England, where it is more studied because it is more widespread, many of the Delta virus positives had already received the first dose of the vaccine, acquiring some protection. Vaccination is a significant shield against severe forms and hospitalizations».
Most affected adolescents and children?
“Yes, it’s true. It depends on the fact that while having fewer receptors for the virus in the cells of the upper respiratory tract, nose and throat become more easily infected as the variant has acquired a higher affinity for the receptors themselves “.
This virus is tempting them all in order not to succumb.
“Exactly so. The Delta variant has new characteristics, it manages to evade the attack of antibodies to a certain extent and it has changed from the structural point in the protein S in such a way as to be able to better recognize the points in which to attach to human cells and penetrate them ».
The reasons for looking to the future positively?
«Let’s read the data of the epidemic in Italy. The positivity rate is around 0.3%, hospitalizations in the medical area are decreasing, those in resuscitation are continuously decreasing, the incidence of Covid-19 is between 10 and 15 cases per 100 thousand inhabitants per week. It means that under these conditions outbreaks, including Delta variant ones, can be easily traced and their expansion limited. And then there is the effect of the summer season. Sunshine, open air, wind. The virus subjected to these natural fighting actions has a short life because it is hindered from spreading via aerosols ».
Is sequencing activity in Italy poor?
“We are gearing up to enhance it. If the percentage of sequencing were higher, over 5%, we could have earlier and statistically significant information. But sequencing is not enough, the effect of each mutation must be studied “.
July 1, 2021 (change July 1, 2021 | 07:17)
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