Flu season is starting, and this year’s vaccine has been changed more than usual. All three virus components were updated for the 2026-27 season, including protection against the H3N2 subclade K strain that spread widely last winter. Health officials say now is the right time to get vaccinated.
What Is New This Year
Every flu vaccine in the United States this season is trivalent, meaning it protects against three viruses: an influenza A (H1N1) strain, an influenza A (H3N2) strain and an influenza B (Victoria) strain. The FDA chose the updated formula in March to better match the viruses expected to circulate.
There is also a new option for older adults. In August, the FDA approved Moderna’s mRNA flu vaccine, called mFlusiva, for people aged 50 and older. The CDC’s interim guidance for this season does not single out any one product, and the overall advice is to take whichever age-appropriate vaccine is available to you.
When to Get the Shot
The CDC says most people should ideally be vaccinated by the end of October, before flu starts spreading in the community. Getting it later is still worthwhile, since flu can circulate from late fall into early spring. Vaccination in July or August is generally not advised for most adults, particularly those 65 and older, because protection can fade over the course of the season.
Protection takes about two weeks to build, so someone exposed to the virus just before or after the shot can still get sick. People who are fully vaccinated this season do not need an extra booster dose.
Who Should Pay Extra Attention
The flu vaccine is recommended for everyone aged 6 months and older. A few groups have specific guidance:
- Adults 65 and older: the CDC prefers a high-dose, recombinant or adjuvanted vaccine when one is available.
- People with an egg allergy: any age-appropriate flu vaccine is acceptable.
- Young children: kids aged 6 months through 8 years who have not had two doses before July 1, 2026 need two doses this season, according to New York City’s health department.
- People at higher risk and their caregivers: including healthcare workers and anyone living with someone prone to complications.
Why It Matters
The CDC’s preliminary estimates for the 2025-26 season point to between 32 million and 57 million flu illnesses and between 390,000 and 800,000 hospitalizations. For the coming months, the agency expects a similar peak in hospitalizations from flu, COVID-19 and RSV combined as last season. Doctors also say eligible people can safely get the flu and COVID-19 vaccines at the same visit, and the flu vaccine cannot give you the flu.
Beyond the Vaccine
Good habits help through the winter months, such as regular sleep, balanced meals and keeping stress under control. If work has left you run down, our guide to burnout recovery is a good place to start. None of this replaces vaccination, though.
Most pharmacies offer flu shots without an appointment, and many insurance plans cover them. If you have questions about which vaccine suits you, ask your doctor or pharmacist.
