UK COVID Cases Rise as XFG ‘American Covid’ Variant Spreads

COVID-19 infections and hospital admissions are increasing across the United Kingdom this autumn, driven largely by the XFG variant, also known as Stratus or nicknamed “American Covid”, according to the latest data from the UK Health Security Agency.

Surveillance figures show COVID-19 activity climbing from a low base. Hospital test positivity rose to around 8.8–9.1% in recent weeks, while weekly hospital admission rates increased to 2.46 per 100,000 people in the week ending 11 October 2026. Detected cases in hospital settings also rose, though overall levels remain low compared with previous winters.

XFG, a recombinant Omicron-lineage variant first sequenced in the United States, has been circulating in the UK and globally for about a year. It now accounts for a significant share of sequenced cases. Health officials emphasise there is currently no evidence that XFG causes more severe illness, higher hospitalisation rates, or greater mortality than other circulating strains.

The uptick is occurring alongside elevated flu activity and rising RSV detections, adding pressure on ambulances and hospitals as colder weather arrives. UKHSA describes overall COVID-19 levels as “increasing but low” and continues to monitor variants such as BA.3.2 (sometimes called Cicada), which the World Health Organization has designated a Variant Under Monitoring with low public-health risk.

Authorities are urging eligible people — particularly those aged 75 and over, and individuals with weakened immune systems — to get their autumn 2026 COVID-19 booster, which is designed to target current circulating strains including XFG. Standard guidance remains in place: stay at home if symptomatic or test positive, and use NHS 111 for non-emergency advice.