Overview
- The CDC says the season has already caused more than 650,000 infections along with thousands of hospitalizations and hundreds of deaths through mid-November.
- Researchers report that subclade K carries mutations that partially evade prior immunity, and the 2025–2026 vaccine was selected before its emergence, potentially reducing effectiveness.
- Wastewater surveillance networks, including WastewaterSCAN, show sustained increases in influenza signal, indicating broader community spread.
- U.S. influenza vaccine shipments total 147.6 million doses this season, about 10 million fewer than last year, raising concerns about coverage.
- Public‑health experts warn of potential hospital strain as nations such as Japan, the UK and Canada saw harsher seasons under K dominance, and they call for full surveillance operations and reinforced hygiene measures.