At the beginning of October, a new subvariant of the coronavirus is spreading more and more rapidly, especially in the United States. Highly transmissible, according to experts it could become the dominant strain in the upcoming winter period, even in Italy. This is “Xec”, with which Italy has already become acquainted at least since last July, when it was “reported” for the first time. Currently present in many countries, it does not appear that Xec in itself leads to a serious illness, without prejudice to the danger of the virus for the weakest groups. However, its rapid transmission is worrying.
Scientifically, Xec is a recombinant variant, that is, a hybrid due to the fusion and reorganization of two other subvariants: Omicron KP.3.3 and KS.1.1. Identified for the first time last June in Germany, in Berlin, it is currently responsible for 5.7% of infections in the United States, and thanks to its high transmissibility it has quickly become the fifth most widespread variant. The virologist Fabrizio Pregliasco also spoke on the Xec subvariant at Adnkronos Salute. “Covid is in an upward phase due to the resumption of schools,” he said.
Xec, the winter variant
We are therefore moving towards a new wave of infections led, precisely, “by the recombinant Xec, which is growing and will certainly be the winter variant”. However, it will take place in a context dominated by a “cocktail of flu-like viruses”, with “symptoms practically indistinguishable between Covid-19 and influenza”. This is why the elderly and frail, explains Professor Pregliasco, “must take a swab to understand what disease it is”. And, consequently, get the right drugs prescribed to avoid serious forms. But let’s proceed in order, taking a look at the updated numbers on the Covid situation in Italy.
The latest data on Covid infections
In the last week, coronavirus cases have increased in our country: 13,073 were recorded in 7 days, compared to 11,164 in the previous period. Swabs are increasing, 95,017, compared to 85,030 7 days ago. However, deaths decreased, amounting to 85 (they were 112 a week ago). The positivity rate grows to 13.8% (previously it was 13.1%). This is the most updated photograph on the state of Covid in Italy in the usual weekly bulletin of the Ministry of Health. The data from the integrated surveillance of the ISS (Higher Institute of Health) relating to the period 23-29 September show an incidence of 21 cases per one hundred thousand inhabitants, an increase compared to the previous week (16-22 September), equal to 16.
The weekly incidence (23-29 September) is slightly increasing in most regions compared to the previous period. The highest incidence was reported in Veneto (41.3 cases per one hundred thousand inhabitants), and the lowest in Calabria, where no cases were reported in the week of observation.
The transmissibility index (Rt) calculated with data updated to 2 October and based on cases with hospital admission, is currently 1.20 and slightly increased compared to the last survey (0.90). Hospitalization and mortality rates are higher in older age groups. Here is a brief breakdown: the hospitalization rate in the 80-89 age group is 75 per million inhabitants, while in the over 90 population it is 143 per million inhabitants. The rate of admission to intensive care in the 70-79 and 80-89 age groups is respectively one and two per million inhabitants. The mortality rate, however, in the 80-89 and over 90 age groups is equal to 5 and 21 per million inhabitants respectively. The age groups that record the highest weekly incidence rate are the same as those mentioned so far: 80-89 years and over 90 years.
The Xec subvariant growing in Italy
The weekly incidence is stable in most age groups. The median age at diagnosis is 60 years, stable compared to the last survey. The percentage of reinfections is approximately 49%: a value that is also stable. The preliminary ISS data relating to the month of September 2024 (and updated to the 29th of the month in question) highlight the co-circulation of different subvariants of JN.1 already the subject of international attention, with a predominance of KP.3.1 .1. Be careful, however: as the Istituto Superiore di Sanità writes in black and white, the proportion of sequences attributable to the recombinant Xec lineage is growing.
The peak of infections in Veneto
Already at the end of September, the local press reported that the Veneto Region was the one with the highest incidence, “with four confirmed deaths and ten hospitalizations in intensive care in 7 days” (data updated to 27 September). In that period, Veneto experienced a “worrying increase in infections”. The new cases in those days (17-24 September) were 1,706, of which 964 women and 742 men. Most were between 45 and 64 years old. The incidence of positive swabs had then reached 35 per one hundred thousand inhabitants, while the previous week they amounted to 24. The national average is stuck at 16: for this reason, according to experts, Veneto has emerged as the region most affected by the subvariant Xec.
The high transmissibility and symptoms
As the case of Veneto demonstrates, Xec increases infections due to its high transmissibility. And what are the symptoms of this subvariant? Professor Vincenzo Baldo, full professor of hygiene and preventive medicine at the University of Padua, provides a general overview. “The symptoms are always the same: fever, muscle pain, tiredness, cough, sore throat. But the Sars-Cov-2 infections have never ended and also affect asymptomatic people”, the expert pointed out. These “can represent a danger for fragile people with whom they come into contact without knowing they have contracted the virus”. And this generally happens because fewer and fewer people resort to tests at the doctor or pharmacy (also because there is no longer an obligation): in fact they prefer a test done at home, or they simply avoid doing the tests.
At present, therefore, Xec does not seem to cause more serious symptoms than those we already know, net of the always worrying effects for older age groups. However, there is one aspect to consider, which does not leave experts calm: its high transmissibility. There does not currently appear to be any change in the behavior of the virus other than increased transmissibility, which has led the new subvariant to supplant “colleague” variants in some areas of Europe. In these areas the rate of infections has increased more rapidly than seen with other subvariants.
The importance of the vaccine
The weapon available to fight the Xec subvariant, experts recall, is the vaccine, suitable for preventing the most serious forms of Covid. This is also because, explains Professor Vincenzo Baldo, “over time, the ability of the virus to cause, in some people, persistent symptoms such as fatigue, breathing difficulties, muscle and joint pain, headaches, problems of concentration and memory and many others which fall precisely into Long Covid and which worsen the quality of life”.
According to experts, the updated Pfizer and Moderna vaccines should also offer some protection against Xec, as it is not possible to guarantee 100% coverage. The vaccine remains a preventive weapon especially against the possible severe form of the disease. This is why it is recommended to undergo vaccination, especially if you are part of a high-risk class of patients.