New COVID XFG variant circulating in Europe: cold-like symptoms

European health authorities are monitoring a new sub-lineage of the SARS-CoV-2 virus, designated XFG, which belongs to the Omicron family. The variant is being tracked by both the World Health Organisation (WHO) and the European Centre for Disease Prevention and Control (ECDC).

XFG was first identified in January 2025 and has been subject to increasingly close surveillance as it has spread across multiple regions. The name "Stratus" has been circulating in public discourse as an informal label for this strain, though it is not the official designation.

How widespread is the XFG variant in Europe

The ECDC has classified XFG as a "variant under monitoring" (VUM). According to data from weeks 34 and 35 of 2026, collected from three European Union and European Economic Area member states, the median proportion of this variant stood at 53.8%.

Specialists caution, however, that this figure cannot be extrapolated to Europe as a whole, as only a limited number of countries have provided sufficient genomic data, giving only a partial picture of the variant's actual circulation.

Ongoing surveillance of SARS-CoV-2 variants remains necessary because the virus continues to evolve, and researchers are monitoring in particular any changes relating to transmissibility, disease severity, and vaccine effectiveness.

Symptoms associated with the XFG variant

A common difficulty is that COVID-19 symptoms are not clearly distinguishable from those of a cold or flu. Possible manifestations include:

• sore or irritated throat
• cough
• fatigue
• fever
• chills
• muscle aches
• nasal congestion
• runny nose
• hoarseness

Loss of smell or taste may still occur, but is no longer as common a symptom as it was in the early years of the pandemic. For this reason, symptoms alone cannot reliably determine whether a person has COVID-19, flu, or a common cold.

How a SARS-CoV-2 infection is confirmed

Testing remains the primary method of confirmation. Rapid tests can be helpful, but a negative result does not automatically rule out infection, particularly if the test is performed too early or symptoms persist. If your condition worsens or symptoms continue, a medical consultation is recommended, with the doctor able to determine whether further tests are required.

Does XFG cause more severe illness?

Based on current information, there is no evidence that the XFG variant causes more severe forms of COVID-19 compared to other Omicron variants. The WHO has assessed the severity risk associated with this variant as low, with no evidence, at the time of evaluation, of increased disease severity.

The ECDC likewise notes that variants currently under monitoring are not associated, according to available data, with an increase in infection severity or a reduction in vaccine effectiveness against serious illness.

The level of risk nonetheless varies from person to person. Older adults, individuals with pre-existing conditions, and vulnerable people may face a greater risk of complications following a respiratory infection.

The emergence of the XFG variant does not signal a return to the critical conditions of the pandemic period; however, the virus continues to evolve and health authorities maintain ongoing surveillance. In the event of severe symptoms — difficulty breathing, chest pain, rapid deterioration of general condition, or persistent fever — it is important to seek medical assistance promptly.