Spain is facing a new wave of coronavirus. According to data from the Acute Respiratory Infection Surveillance System (SiVIRA) of the Carlos III Health Institute, the global case rate in the week of October 28 to 4 stands at 493.8 cases per 100,000 inhabitants, 3.3% more than the previous week (478.2).
As reported by the Medical Editorial Media, although the level of intensity of the pandemic is still "low", there have already been several weeks in which increases in incidence have been chained.
Behind this increase is the XFG variant, which is already dominant in Spain and much of Europe. The good thing is that for now, there is no evidence that this variant is more dangerous than others.
Medical Editorial cites sources from the Spanish Society of Infectious Diseases and Clinical Microbiology (Seimc), which states that "there is a real rebound in transmission, not simply a statistical fluctuation."
According to this medium, in week 39, the rate of respiratory infections had grown by 28.2% at once, and the specific incidence of covid was close to 120 cases per 100,000 inhabitants.
Another positive fact is that there is no impact on the number of hospital admissions. "A variant with greater transmission capacity can also generate a significant number of hospitalizations simply because it infects more people, although the risk of severity due to infection has not increased," says the Seimc.
XFG is a recombinant lineage of SARS-CoV-2, belonging to the Ómicron/JN.1 family, which arose from the recombination of two Ómicron sublineages. The WHO classified it in June 2025 as a "variant under monitoring" because it showed a growth advantage over other lineages, but does not consider it a variant of concern.
XFG "presents several mutations in the Spike protein, some of them in regions related to interaction with antibodies." But for now, the available studies "indicate that their immune escape capacity is only modestly different from that of other JN.1 descendants," says Seimc.
"The European Center for Disease Prevention and Control (ECDC) estimated that XFG represented around 54% of sequences reported in European countries with sufficient data during weeks 34 and 35 of 2026," so its dominance is beyond doubt.
According to the Seimc, the data from the Surveillance System showed around 69% of XFG among the variants characterized in Primary Care and around 65% among hospital samples.
"XFG and its descendants play an important role because they constitute a majority of the viruses that are circulating, but proving that the current increase in cases is due exclusively to this variant is much more difficult," says the Seimc in any case.
In any case, the Seimc says that "there is no evidence that XFG produces a more serious covid-19 than the remaining Ómicron variants currently circulating."
It also has no symptoms of its own. "There is currently no specific clinical picture of XFG that allows it to be differentiated from other variants," sources from this scientific society tell Medical Writing.
In any case, the usual symptoms of the recent variants predominate: sore throat, rhinorrhea or nasal congestion, cough, fever or chills, headache, muscle aches and tiredness; loss of smell or taste is much less common than in the early phases of the pandemic.
The five factors that have triggered the cases
According to the Seimc, these are the five factors that have caused coronavirus cases to continue to increase in recent weeks:
