A ‘super flu’ strain is making everyone sick. Is this year’s vaccine effective?
NJ.com••health
Key Points:
- A new mutated strain of influenza A(H3N2), called subclade K, is driving a surge in flu infections across the U.S., including the first pediatric flu death of the season in New Jersey, with the CDC estimating at least 180,000 hospitalizations and 7,400 deaths so far.
- Subclade K emerged after the 2025-2026 flu vaccine was developed, leading to some mismatch and reduced vaccine coverage, but preliminary data shows the vaccine remains 70-75% effective in children and 30-40% effective in adults at preventing hospital visits.
- Despite the vaccine’s effectiveness, flu vaccination rates among children have declined significantly, raising concerns among health experts who emphasize that vaccinated individuals generally experience
