Overview
- CDC estimates through Jan. 3 put the toll at roughly 15 million illnesses, 180,000 hospitalizations and 7,400 deaths, including at least 17 children.
- Some surveillance measures eased the week ending Jan. 3—fewer flu-related office visits and fewer states at high activity—yet hospitalizations and deaths remained elevated and officials say it is unclear the season has peaked.
- H3N2 accounts for more than 92% of tested influenza A samples, and about 91.5% of H3N2 viruses are the subclade K variant that differs from the vaccine strain; UK data show 70–75% effectiveness against pediatric ED visits and hospitalizations and about 30–40% in adults.
- Emergency departments report sustained strain in the U.S., and four NHS hospital trusts in England declared critical incidents as flu admissions rose early in January.
- Federal guidance removed universal childhood flu vaccination from the routine schedule in favor of high‑risk or clinician‑advised decisions, while clinicians continue to urge vaccination and early antivirals, with studies showing oseltamivir substantially lowers hospitalization risk in high‑risk outpatients.