The sub-variant
of Omicron called
BA.2
has also arrived in Italy
: it is just as fast in spreading, but it is not yet clear whether it is less aggressive.
It is not the only sister of Omicron: there are also
BA.1
and
BA.3
, as indicated by the large databases that store the sequences of the SarsCoV2 virus, such as
NextStrain
and
Gisaid
, so much so that some experts speak of a "
hypermutated version .
"of the SarsCoV2 virus, as does the founder of the Scripps Institute, Eric Topol. According to Tom Peacock, of Imperial College London," BA.2 is unlikely to generate a new wave ": rather it could ruin the current wave or slow down the descent of the epidemic curve.
Of the three versions of Omicron, BA.1 is the most widespread: in the countries where it arrived, it quickly put aside the pre-existing variants. It also happened in
Italy
, where Omicron has replaced Delta and as of January 17 had an estimated prevalence of 95.8% (with a margin of uncertainty between 83% and 100%) according to the rapid survey conducted by the Higher Institute of Health (ISS) and the Ministry of Health , with regional laboratories and the Bruno Kessler
Foundation
BA.2 was reported in
India
and then in the
Philippines
,
Singapore
and
Japan
; he also added Europe, where the sequences were identified in some Scandinavian countries, including
Denmark
, and then in
Great Britain
and
Germany
.
Italy
has
now entered among the countries in which BA.2 is present, with the two sequences obtained in the Hygiene Laboratory of the San Martino Polyclinic in Genoa. "It has been reported in
9 regions
," said ISS president Silvio Brusaferro.
The reconstruction of the sequences by the Nexstrain database indicates that the
three variants
of the Omicron
family
are as
different from each other
as the Omicron is compared to the other variants that have appeared so far, such as Delta, Alpha or Beta. What consequences such a changing virus may have on the progress of the pandemic is currently not possible to say; it is clear only that the SarsCoV2 virus has a great ability to generate new variants.
Genetic data indicate that
BA.1
is the most common sub-variant;
BA.2
is a little less so, but in some cases it has taken over BA.1: it happened in Denmark, Nepal and the Philippines, but not in India and Great Britain; the
BA.3
it is not yet widespread, with a few hundred sequences deposited so far.
The data then indicate that the three sub-variants
separated
from Omicron in
March 2021
: first appeared BA.1 (with 20 new mutations compared to the original Omicron, 13 of which were unique) and BA.2 (with 27 new mutations). , 10 of which are unique and none are communicated to BA.1);
BA.3 then differentiated from BA.2 (13 new mutations, 1 unique, 5 common to BA.1 and 7 common to BA.2)
