American Covid Variant XFG: Symptoms and UK Cases Explained
- COVID-19 infections in the UK jumped 230 percent between August and September according to the UK Health and Security Agency, rising from 1,374 cases to 4,589.
- Despite the steep upward trajectory in reported cases—accompanied by hospitalisations climbing from 950 in August to 4,939 in September according to the UK Health and Security Agency—official bodies...
- Genomic surveillance data from the UK illustrate how the lineage has spread.
COVID-19 infections in the UK jumped 230 percent between August and September according to the UK Health and Security Agency
, rising from 1,374 cases to 4,589. The sharp increase coincides with the circulation of the XFG variant, also referred to as “American Covid” or “Stratus Covid,” which health authorities are monitoring this autumn alongside a concurrent rise in hospital admissions.
Despite the steep upward trajectory in reported cases—accompanied by hospitalisations climbing from 950 in August to 4,939 in September according to the UK Health and Security Agency
—official bodies emphasize that overall viral levels remain low. Alex Allen, a consultant epidemiologist at the UKHSA, stated: While Covid-19 activity has shown some recent increases, cases remain at low levels in the UK. UKHSA is monitoring all the data relating to Covid-19 variants in the UK and abroad, and we continue to publish our findings in our regular surveillance reports.
Furthermore, current evidence does not indicate that XFG causes more severe disease than other circulating variants, and the World Health Organization currently classifies XFG as a Variant Under Monitoring rather than a higher-risk threat.
Variant Lineages and Hospital Pressures
Genomic surveillance data from the UK illustrate how the lineage has spread. In samples sequenced between August 17 and August 30, the XFG.23.1.3 sub-lineage accounted for 46.2 percent of sequenced cases, while XFG.14.8 made up 12.8 percent and the original XFG lineage represented 5.1 percent. Official figures show that the overall COVID-19 hospital admission rate in England rose to 1.20 per 100,000 in week 38 of 2026, up from 0.81 per 100,000 the previous week. Regionally, London saw its admission rate climb from 0.95 to 1.70 per 100,000, with people aged 85 and older experiencing the highest rate at 12.43 per 100,000.
Recognising Symptoms and Vulnerable Groups
While reports note that symptoms cannot specifically identify an XFG infection and closely mirror other respiratory strains, distinct characteristics have been highlighted for those watching for the virus. Typical signs include a persistent dry cough, fatigue, a high temperature of 38C or above, sore throat, headaches, muscle aches, congestion, runny nose, and gastrointestinal issues such as nausea, loss of appetite, stomach aches, and diarrhea. Stony Brook Medicine noted that most individuals experience mild effects—particularly if vaccinated or boosted—though the virus can still cause extreme illness in elderly and vulnerable individuals with weakened immune systems.