Federal health guidance says almost everyone age 6 months and older should get a flu shot every single year, and this season brings a new vaccine choice for older adults.
Quick Take
- The Centers for Disease Control and Prevention (CDC) recommends annual flu vaccination for nearly everyone 6 months and older, with rare exceptions.
- A new mRNA-based flu vaccine called MFLUSIVA is now approved for adults 50 and older, using different approval paths for the 50-64 and 65-plus age groups.
- Best timing is September or October, before flu activity peaks, according to CDC’s vaccine advisory group.
- Real-world effectiveness swings widely by season and strain, from around 35% to over 40% in recent years.
- Serious side effects remain extremely rare, with roughly 1 to 2 extra Guillain-Barré cases per million doses in years when any added risk shows up at all.
A Yearly Shot, Not a One-Time Decision
Flu vaccination is not a one-and-done deal. The virus shifts shape constantly, so manufacturers update the formula most years. CDC guidance says people age 9 and older need one dose of the current season’s shot, while some younger children need two doses depending on their vaccine history. Waiting until flu is already spreading in your town means you missed the ideal window.
Health officials urge most people to roll up their sleeves in September or October. That timing gives the body enough time to build protection before flu season typically ramps up in late fall and winter. Pharmacies, clinics, and the Department of Veterans Affairs have already launched fall vaccination pushes, including a 2026 campaign from the VA’s Montana health system aimed at getting veterans covered early.
A New Shot Option Lands for Adults 50 and Older
This season’s biggest headline is MFLUSIVA, a new mRNA flu vaccine. The Food and Drug Administration gave it traditional approval for adults 50 to 64 and a faster, accelerated approval pathway for those 65 and older. That distinction matters because accelerated approval often comes with continued data collection even after a product reaches pharmacy shelves. It is one more tool, not a replacement for every existing vaccine option.
For decades, flu shots meant inactivated or recombinant vaccines, plus a nasal spray for younger, healthy people. CDC still lists those standard options for people under 65 and specifically prefers high-dose, recombinant, or adjuvanted formulas for seniors, who tend to mount weaker immune responses with age. The new mRNA shot adds competition to that lineup rather than erasing it, and supply or insurance coverage may still vary by clinic and region.
How Much Protection Should You Actually Expect
Nobody should expect a flu shot to work like a force field. Effectiveness moves up and down depending on how well that year’s formula matches the circulating strains. CDC’s own preliminary estimate for the 2021-2022 season put protection against moderate-to-severe influenza A(H3N2) illness at about 35%. Broader academic reviews covering multiple seasons have found pooled effectiveness closer to 41% against medically attended, lab-confirmed flu.
That gap between a flashy marketing number and the messier real-world data is exactly why health officials keep saying “talk to your doctor” instead of citing one flat percentage. Age changes the math too. Reviews looking specifically at adults 65 and older found effectiveness dropping to roughly 31% in some seasons, reinforcing why CDC steers seniors toward stronger-dose products.
Weighing the Rare Risks Against the Common Benefit
Every vaccine carries some risk, and flu shots are no exception. CDC’s clinical safety guidance tracks Guillain-Barré syndrome, a rare nerve disorder, and found that in seasons where any increased risk appeared, it amounted to about 1 or 2 extra cases per million people vaccinated. That is an exceedingly small number compared to the millions of Americans who get hospitalized or die from flu complications most years, a trade-off readers weighing personal risk against public benefit should find reassuring rather than alarming.
Today is the day!!! The Montana VA Health Care System's 2026 Flu vaccination campaign is beginning soon at a location near you.
Come out and see us, and get your free flu vaccine. Montana VA’s Flu Shot Clinic Schedule (by location) can be found here: https://t.co/hBa17oAcjI… pic.twitter.com/GYs64VAz30
— Montana VA Health Care System (@VAMontanaHCS) October 6, 2026
The bottom line from federal health officials remains simple even as the product lineup grows more complex. Get vaccinated in early fall, ask your pharmacist or doctor which formulation fits your age and health history, and don’t let headlines about new mRNA options distract from the basic fact that annual flu vaccination remains the recommended path for nearly every American six months and older.
