[ad_1]
It is called VUI-202012/01 or lineage B.1.1.7 and it is the new variant of the Sars-Cov-2 coronavirus that emerged in mid-September in the southeast of England for which, only in the last hours, Italy and others European countries, including France, Germany, Belgium, the Netherlands and Austria, have decided to block flights arriving from Great Britain. The fear is that the new variant, considered 70% more contagious by UK health authorities – it may land alongside those returning to Europe for the Christmas holidays, unleashing a third wave that would overlap with the vaccination campaign being carried out in EU countries. An evidently late action against a mutation that, in a few months, has become predominant in the south-east region of England, and that therefore, he had a lot of time to “travel” in the Old Continent. In Italy, for a few days, a person and “his partner” – as described by the Ministry of Health in an official note – have been hospitalized in the Celio military hospital in Rome, where doctors have found the positivity of one of the two to the new variant. Both had recently returned from England when they first felt symptoms. Another man, a doctor, presumed positive for the new variant, was subjected to investigations in Spallanzani. A situation that triggered security measures against close contacts, just when passengers were alerted on their flights back to Italy, generating not a little apprehension because through the classic molecular swab it is not possible to know if one has been infected. of the new variant.
How is the new variant of the coronavirus detected?
As is known, the traditional diagnostic test, or molecular swab, detects the presence of genetic material of the Sars-Cov-2 virus in a gold / rhino-pharynx sample. Therefore, by this test it is not possible to know which variant of the virus it is, but only if the infection is ongoing and possibly the associated viral load.
To find out if you have been infected with the new variant, you need a much more comprehensive examination, namely the sequencing of the virus genome, which can be complete or partial, also by virtue of the new information about the mutations present in the variant. In particular, it was found that, at the level of the Spike protein, which the coronavirus uses to bind to the cellular receptor ACE2, the new variant shows eight different mutations, between amino acid substitutions and deletions. Mutations that could, among other things, reduce the efficiency of the diagnostic test, as the test relies on “probes” (one to four depending on the reagent manufacturer) capable of adhering to specific nucleotide sequences. : In the presence of substantial viral variants, such probes may therefore not be effective.
On the other hand, also rapid antigen tests, that is, those that recognize the same Spike protein, could be ineffective, since it has not yet been clarified whether the mutations present in the new variant are capable of evading the control or not, with the risk of being negative when instead it is positive for the version. mutated virus.
In this regard, following the emergency meeting of the European Center for Disease Control (ECDC), the EU Agency pointed out the need for European laboratories to recheck and update the various diagnostic methodshence the sequences used to detect the presence of Sars-Cov-2 using molecular swabs and antigen tests. According to the ECDC, for the correct identification of the new variant, it will not be possible to depend solely on the detection of mutations in the gene that encodes the viral protein Spike, but it will be necessary to have confirmation using gene sequencing. A recommendation that, at least in this first phase, could clash with the Italian situation, where laboratories have not received funding to implement a genetic sequencing that allows the identification of virus variants. In fact, very few sequences have been performed in our country, as confirmed by the few data shared by Italian researchers in international databases such as GenBank and Gisaid.
[ad_2]
