Flu Vaccination for 2026-2027: New Vaccine, No ACIP, Same Advice

Leading up to the 2026-27 flu season, two headlines might have caught your attention. The first is that the mRNA flu vaccine got approved. The second is that the Advisory Committee on Immunization Practices (ACIP), the committee that normally tells you how to use the vaccine, didn't meet. 

Neither of these changes much about what you'll do in your clinic though. Here's what you need to know for the upcoming flu season.

Last season set a low bar

The 2025-2026 flu season was driven mainly by influenza A H3N2 subclade K — a drifted virus that the CDC didn't identify until June 2025, months after the vaccine strains were already locked in for production. It accounted for 93% of H3N2 samples.

As a result of this mismatch, effectiveness was low. Vaccine effectiveness was about 40% in children and even lower (22% to 34%) in adults. But influenza B was the bright spot. Vaccine effectiveness for that strain was between 45% to 71% in children and 63% in adults.

For the patient who says the shot didn't work, it’s worth knowing that in 2022-2023, vaccine effectiveness was also very low at 30%, but vaccination still prevented an estimated 71,000 hospitalizations and 4,300 deaths.

All three vaccine viral components are new

The FDA updated every component of the vaccine for 2026-2027: H1N1, H3N2, and Flu B. The H3N2 change is the one that matters since that’s what drove last year’s poor effectiveness. Everything on the U.S. market remains trivalent this year.

Don't oversell the update, though. Strains get picked in March for a season that peaks in December, so there’s always a mismatch. This year’s match should be better than last year’s because the H3N2 subclade K is specifically being targeted, but there are no guarantees.

First mRNA flu vaccine approval

The FDA approved mFlusiva in August for adults 50 years of age and older. It’s the first mRNA flu vaccine to reach the U.S. market.

In FLUENT, a trial of over 40,000 patients, PCR-confirmed influenza occurred in 2% of mFlusiva recipients versus 2.8% on a standard-dose vaccine. That's a 27% relative reduction, which met criteria for noninferiority, superiority, and higher-level superiority. 

Side effects roughly doubled though, compared to the standard-dose vaccine: 

• Injection-site pain: 66% versus 30%

• Fatigue: 45% versus 20%

• Headache: 38% versus. 18%

• Myalgia: 35.4% versus 11.6%

Serious adverse events were comparable to standard flu shots, with no myocarditis or pericarditis.

Note that the trial compared mFlusiva to a standard-dose shot only. It was never compared to Fluzone High-Dose, Fluad, or Flublok — the three flu vaccines preferred in patients aged 65 and older. It also wasn't powered to assess for outcomes regarding hospitalization or death.

Here’s a quick look at what this means for flu shot recommendations this year.

There's no ACIP statement this season

The CDC's flu guidance hasn’t been updated, and the website still shows the 2025-2026 document. A federal judge stayed the appointments of ACIP members in March 2026, and ACIP’s scheduled March and June meetings were subsequently canceled while litigation continued.

What this means is that you're working from last year's recommendations: 

• Everyone 6 months and older should be vaccinated, ideally in September or October.

• There’s no product preference, except the high-dose, adjuvanted, or recombinant preference in patients over 65.

• Egg allergy still requires nothing special.

The good news is that even though ACIP hasn’t met, various medical societies have filled the gap and didn't diverge:

• The American Academy of Pediatrics (AAP) recently published its 2026-2027 policy statement.

• The American Academy of Family Practice (AAFP) and American College of Obstetricians and Gynecologists (ACOG) published 2026 adult and pregnancy schedules, which the American College of Physicians (ACP) Immunization Committee voted unanimously to support. 

• The Infectious Diseases Society of America (IDSA) has provided recommendations for vaccination in immunocompromised patients.

Coverage is the real wrinkle

While FDA approval lets a product be sold, ACIP recommendations are what forces insurers to cover it at no cost. So while ACIP’s absence doesn’t affect the recommendations you give your patients, it can affect whether your patients’ flu shots are covered by insurers:

• Medicare Part B covers flu vaccines by statute, so patients 65 years and older pay nothing regardless.

• Private plans and Medicaid rely on ACIP though. With no recommendation for mFlusiva, none are obligated to cover it.

• Insurers have a voluntary commitment to cover recommendations in place before September 2025, which predates mFlusiva.

In other words, a 68-year-old is fine since they have Medicare. A 55-year-old on commercial coverage may get billed for mFlusiva specifically though.

Because of this confusion and recent trends, it’s possible that more people will go unvaccinated this year than in years past. So keep this in mind when you see patients with flu-like symptoms. It’s a good idea to start antiviral medication early in anyone high-risk, deteriorating, or hospitalized. Don't wait on confirmatory testing.

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Written by:

Farzon A. Nahvi, MD

Farzon Nahvi, MD, is an emergency medicine physician and author of “Code Gray: Death, Life, and Uncertainty in the ER.” He works at Concord Hospital in Concord, New Hampshire, and teaches at the Geisel School of Medicine at Dartmouth.

Edited by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined clinical medicine with her passion for education and content development for many years. She is co-executive director at Nonclinical Physicians Network and has served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

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