Tejal Somvanshi
Hospital admissions linked to COVID-19 have been climbing week on week in England. The most prevalent sublineage identified in recent UK surveillance is XFG.23.1.3, an XFG-related variant, which has also been called “Stratus” in health media coverage. If you are over 75, immunocompromised, or live with someone in either group, the practical questions are specific: how does XFG behave clinically, whether you qualify for a booster, and when symptoms warrant urgent care rather than home rest.
XFG is a recombinant descendant of previous SARS-CoV-2 FLiRT variants — it is not a new disease, it is the latest evolution of the coronavirus that has circulated since 2020. UK Health Security Agency (UKHSA) sequencing data shows XFG sublineages, most prominently XFG.23.1.3, now account for a substantial proportion of circulating COVID-19 cases in England. In the 24 September 2026 UKHSA surveillance report, XFG.23.1.3 accounted for 46.2% of sequenced samples, while XFG itself accounted for 5.1%. Hospital admissions have increased week on week through September and into October 2026, with rises concentrated among older adults and those with underlying health conditions. The NHS autumn booster programme is running now for eligible groups. Intensive care admissions remain low and stable compared with earlier wave peaks.
The XFG variant frequently presents with a notably hoarse or rough voice, intense sore throat, muscle aches, fatigue, and fever. Gastrointestinal symptoms — nausea, stomach cramps, loose bowel movements — have been reported alongside the main respiratory symptoms. If you are aged 75 or over, live in a care home for older adults, or are immunosuppressed and aged six months or over, you are among the groups offered the autumn 2026 COVID-19 vaccine in England. Appointments can be booked through the NHS National Booking Service or at participating community pharmacies. A recent booster does not prevent infection, but it reduces your risk of serious illness.
Does XFG cause more severe illness than earlier variants?
Current evidence does not establish that XFG causes more severe disease by itself. Clinical risk remains driven by age, underlying conditions, and vaccination status — not by any unique property of this specific variant. The same protective approaches that applied to previous autumn waves remain effective.
UKHSA surveillance data shows that the current rise in hospitalizations is predominantly patients admitted with a positive COVID test rather than for acute respiratory distress. Many are elderly patients admitted for other conditions who test positive during routine hospital screening. That distinction matters when interpreting the headline admission numbers: the figures reflect broad community circulation, not a step change in disease severity for healthy adults.
Loss of smell or taste — a hallmark of earlier variants — is reported far less commonly with XFG. The dominant presentation is upper-respiratory, closer in character to a severe seasonal cold or flu. Symptoms overlap considerably with other respiratory infections, including influenza; the only reliable way to confirm a COVID-19 diagnosis is a test.
“American COVID” is a media nickname, not an official epidemiological designation. XFG has been identified in multiple countries simultaneously. Its prevalence in both the US and UK reflects shared seasonal patterns and naturally declining antibody levels across vaccinated populations over time.
If you test positive, stay home until you have been free of fever for at least 24 hours and your symptoms are clearly improving. Keep distance from elderly or clinically vulnerable contacts during that period. Call NHS 111 if symptoms worsen sharply — particularly breathlessness, a high fever that fails to reduce with standard medication, or confusion.
A full breakdown of who qualifies for the NHS autumn booster in 2026, including the complete clinical-vulnerability list, is available in our separate guide. If you are caring for someone who is immunocompromised and unsure about their eligibility, speaking to a pharmacist before booking will clarify whether an updated dose is appropriate. For practical winter respiratory illness guidance covering COVID, flu, and RSV, including when to test and when to call ahead before attending a GP surgery, see our winter health overview.
UKHSA publishes a weekly COVID and influenza surveillance report. If admission rates begin to fall or if clinical severity signals change, we will update this piece with the latest figures.
