Overview

• UKHSA’s first weekly report of the 2025–26 season shows test positivity increasing, and the NHS booking system is open for eligible flu and COVID-19 jabs.
• Stratus (XFG and sublineages) accounts for roughly four in five sequenced infections in recent UK surveillance, and the WHO lists it as the dominant strain across the country.
• NB.1.8.1 (Nimbus) remains under WHO monitoring as a Variant Under Monitoring and is circulating but not the leading strain.
• Clinicians report frequent hoarseness and laryngitis‑like symptoms with Stratus, while Nimbus has been linked to a razor‑sharp sore throat and more gastrointestinal complaints.
• Officials say current data does not indicate greater severity from these variants, and guidance stresses vaccination, avoiding vulnerable people when symptomatic, face coverings in public if ill, and early testing for high‑risk patients who may be eligible for antivirals.