'K-strain' Flu Outbreak in Britain: Severe Symptoms and Rising Cases Fuel Concern Wednesday, December 10, 2025 kstrain influenza h3n2 flu ukhealth mutation symptoms outbreak virus immunity Britain is currently grappling with an outbreak of the ‘K strain’ influenza, a new variant of flu that has rapidly spread across the country in recent weeks. Identified as the “subclade K” variant of Influenza A … Read More