Biology and Life Sciences #subclade K symptoms

As H3N2's subclade K surges in December 2025, evading immunity with seven mutations, this guide explains its razor-throat symptoms, rapid spread across 34 countries, and vaccine mismatch risks for a potentially brutal 2026 season—armed with prevention tactics.

As 2025 winds down, a new H3N2 variant—subclade K—armed with seven key mutations is igniting fears of a severe 2026 flu season. This real-time tracking guide breaks down the strain's rise, global spread, vaccine challenges, and protective strategies to stay ahead of the surge.