New criteria for the analysis of swabs with a high viral load are needed to be able to identify the Delta variant (the Indian variant according to the old terminology): the appeal to change the criteria for screening as soon as possible comes from the virologist Francesco Broccolo, of the University of Milan Bicocca.
"At the moment we do not have a precise picture of the circulation of this variant, contrary to what happens in Great Britain, where a national program for sequencing is active," the virologist told ANSA.
The current procedure consists in swabbing and, if positive and with a high viral load, a second test is carried out, designed to specifically verify the presence of the Alpha variant, i.e. the English variant according to the old terminology. "This was fine months ago, when it was an exception to find the Alpha variant, but today - Broccolo observes - the Alpha variant is present in 95% positive swabs". That is to say that "Alfa is now the new basic virus", which replaced the most widespread version of the SarsCoV2 virus until a few months ago. Considering then that, in addition to the Delta variant, also Beta (formerly South African) and Gamma (formerly Brazilian) "escape vaccines after the first dose and in some cases after the second".
It is difficult to say whether, as happened in Great Britain, also in Italy the Delta variant can replace the Alpha variant, becoming dominant: the answer, according to Broccolo, depends on numerous factors. The first is in the same vaccination campaign as clinical data on vaccinates indicate that after the first dose of the AstraZeneca vaccine the coverage against the Delta variant is 33.5% against 51% for the Alpha variant and similar values are found for Pfizer-BioNTech's vaccine. "Doing the recall provides a marked difference in protection.
Second," screening is needed for highly charged positive swabs taken at airports, gyms, schools and for events open to large numbers of people. "
Another element, evident in Great Britain, is that "the Delta variant is spreading a lot among young people, both through the presence of two mutations, called 452 and 478, and through the social habits of young people. Consequently" the contagion is very high, but the numbers are under control in terms of hospitalizations and intensive care ", observes Broccolo." At the same time - he continues - adults are keeping more attention, generally the elderly population is more careful and already vaccinated with the second dose " .
As for Italy, for the virologist it must be considered that "the vaccinated with a double dose are 25% and 50% have had only the first dose: this means that in the summer the virus could find a way of access and that the situation could be more serious than in Great Britain because we are still behind in the vaccination campaign ". There is also the risk that during the summer travel and travel could favor the appearance of new variants and "make it necessary to develop a new vaccine". For this, he concludes, "it is still very important to continue to use masks, respect the distance, disinfect and wash your hands".