U.S. flu shots fully updated for next flu season

CDC says all three ingredients in the 2026-2027 U.S. flu shot are new from 2025-2026, including A/Missouri/11/2025 (H1N1) and A/Darwin/1454/2025 for egg-made shots. Think updated locks for new keys. Shots cover ages 6 months and up, best in September-October for one dose. My take: a fresh start makes matching winter flu higher-stakes.