Americans heading to the pharmacy for a flu shot this fall may encounter a choice they have never seen before.
For the first time, the United States has an FDA-approved mRNA vaccine for seasonal influenza.
The vaccine, called MFLUSIVA, is made by Moderna and uses the same general type of mRNA technology that became familiar to millions of Americans during the COVID-19 pandemic. But this vaccine is designed specifically to protect against seasonal influenza.
The U.S. Food and Drug Administration approved MFLUSIVA on August 5, 2026, for adults 50 years of age and older. Adults ages 50 through 64 received traditional approval, while the indication for adults 65 and older was approved under the FDA’s accelerated approval pathway based on immune-response data, with additional research required to confirm clinical benefit in that older group.
Read the FDA information for MFLUSIVA
But consumers walking into a pharmacy this fall could understandably find the situation confusing.
That’s because FDA approval and federal vaccine recommendations are not the same thing.
And the federal recommendation process for the 2026–2027 flu season is unusually complicated.
First, What Exactly Is MFLUSIVA?
MFLUSIVA is a trivalent influenza vaccine manufactured by Moderna.
Instead of using traditional flu-vaccine manufacturing methods, it uses messenger RNA, or mRNA, to instruct the body’s cells to temporarily produce influenza proteins that the immune system can learn to recognize.
The vaccine itself does not contain influenza viruses and cannot cause the flu.
According to Moderna’s patient information, MFLUSIVA also does not contain egg protein, antibiotics or preservatives.
See Moderna’s MFLUSIVA information for patients
This year’s vaccine is designed to protect against three influenza viruses expected to circulate during the 2026–2027 season.
All U.S. flu vaccines this season are trivalent, meaning they target three influenza virus components. The FDA updated all three components compared with the 2025–2026 season.
Who Is MFLUSIVA Approved For?
This is where consumers need to pay attention to the wording.
The FDA has approved MFLUSIVA for people age 50 and older.
But there are two different regulatory pathways within that approval.
For adults 50 through 64, MFLUSIVA received traditional FDA approval.
For adults 65 and older, the indication received accelerated approval based on immune-response results. Continued approval for that older age group may depend on a confirmatory study verifying its clinical benefit.
So saying that MFLUSIVA is FDA-approved only for ages 50 through 64 would be incorrect.
It is approved beginning at age 50.
The type of approval differs once a person reaches 65.
Why Is the 50-to-64 Age Group Especially Interesting?
For years, people in their 50s and early 60s have generally had several flu-vaccine choices, but there has not been a nationally preferred vaccine specifically for their age group.
CDC’s current guidance says that for people younger than 65, there is generally no preference for one licensed, age-appropriate influenza vaccine over another.
That means a healthy 55-year-old walking into a pharmacy does not ordinarily need to search for one particular brand of flu vaccine simply because of age.
MFLUSIVA now adds a fundamentally different type of vaccine to those choices.
And its clinical trial results attracted attention.
What Did the MFLUSIVA Study Find?
The FDA’s review included a large late-stage clinical trial involving more than 40,000 adults age 50 and older.
For adults ages 50 through 64, MFLUSIVA was compared with a licensed standard-dose influenza vaccine.
Reuters reported that MFLUSIVA showed 26.6% greater effectiveness against influenza than the standard-dose comparator vaccine in the study.
That number needs some context.
It does not mean MFLUSIVA prevented 26.6% of all influenza cases or that another flu vaccine was ineffective.
It represents relative vaccine efficacy compared with the other vaccine used in the clinical trial.
The FDA’s review concluded that the clinical evidence supported a favorable benefit-risk profile across the approved population.
What About People 65 and Older?
The situation changes somewhat at age 65.
MFLUSIVA is FDA-approved for people 65 and older, but that indication received accelerated approval based on immune-response data.
Moderna is conducting additional research to confirm the clinical benefit for that age group.
There is another important consideration.
Existing CDC guidance has long given people 65 and older preferential recommendations for certain flu vaccines.
CDC’s current interim guidance says adults 65 and older should preferentially receive one of three types:
High-dose inactivated influenza vaccine
Recombinant influenza vaccine
Adjuvanted inactivated influenza vaccine
If one of those isn’t available when someone has an opportunity to be vaccinated, CDC says another age-appropriate flu vaccine can be administered.
That makes the decision for a 68-year-old potentially different from the decision for a 58-year-old.
So Why Is Federal Guidance Complicated This Year?
This is the part consumers may encounter in headlines without much explanation.
FDA approval determines whether a vaccine can legally be marketed for a particular indication.
CDC recommendations are a separate process that guides how vaccines should be used in the population.
Normally, the Advisory Committee on Immunization Practices, or ACIP, reviews vaccine evidence and develops recommendations that ultimately inform CDC guidance.
But that process has been disrupted.
CDC’s September 1 interim clinical considerations explicitly state that because of legal uncertainties and inquiries, recommendations from the July 2025 immunization schedule remain in effect for the 2026–2027 influenza season.
A federal court order stayed actions taken during several ACIP meetings and affected subsequent CDC immunization policy decisions. CDC now labels the current recommendations as interim clinical considerations.
The practical result is unusual:
A brand-new flu vaccine has received FDA approval while the normal federal recommendation process has been disrupted.
MFLUSIVA Isn’t Specifically Included in CDC’s September Interim Guidance
That distinction is particularly important.
The current CDC interim flu guidance was published September 1.
MFLUSIVA had received FDA approval several weeks earlier, on August 5.
Yet the September CDC interim document does not specifically incorporate MFLUSIVA into its vaccine recommendations.
Immunize.org, a nonprofit immunization organization widely used by healthcare professionals, specifically notes that CDC’s September 1 interim clinical considerations do not contain information about MFLUSIVA, even though FDA licensed the vaccine on August 5.
That doesn’t mean the FDA approval disappeared.
It means consumers are seeing two different pieces of the vaccine system moving on different tracks.
FDA Approval and CDC Recommendation Answer Different Questions
This distinction is easy to miss.
When the FDA approves a vaccine, the agency has evaluated evidence concerning areas including safety, effectiveness, manufacturing and the benefit-risk balance for the indicated population.
CDC recommendations address another question:
How should that vaccine be used as part of the nation’s vaccination strategy?
Those processes normally work closely together, which is why most consumers rarely need to think about the difference.
This fall, they may.
Does CDC Still Recommend Flu Vaccination?
Yes.
Despite the unusual policy environment, CDC’s current interim clinical considerations continue to recommend routine annual influenza vaccination according to the schedule that remains in effect.
CDC says people should receive an FDA-licensed influenza vaccine appropriate for their age, with specific exceptions and considerations for certain populations.
The agency’s consumer guidance also continues to say that everyone 6 months and older, with rare exceptions, should receive a flu vaccine every season.
Read CDC’s current 2026–2027 influenza vaccine guidance
Do Adults 50 to 64 Need MFLUSIVA Instead of Another Flu Shot?
Not based simply on their age.
MFLUSIVA gives adults 50 through 64 another FDA-approved option, but CDC’s current guidance does not say that everyone in this age range should seek it instead of another appropriate flu vaccine.
For people younger than 65, CDC currently says there is no preferential recommendation for one licensed, age-appropriate influenza vaccine over another, subject to certain exceptions.
That’s an important point for anyone who sees headlines about the new vaccine and worries that the flu shot already available at their pharmacy is suddenly outdated.
It isn’t.
MFLUSIVA is an additional option, not evidence that existing approved flu vaccines have stopped being appropriate.
What Should You Ask at the Pharmacy?
The new vaccine makes a few simple questions more useful this year.
If you’re 50 or older and interested in MFLUSIVA, ask:
Do you carry MFLUSIVA?
Is it appropriate for my age and medical history?
Is it covered by my insurance plan?
And if you’re 65 or older:
Which flu vaccine are you recommending for my age, and why?
A pharmacist or healthcare provider can take into account factors that a headline cannot, including age, allergies, previous vaccine reactions, immune status and other medical considerations.
Don’t Assume Every Pharmacy Will Have It
FDA approval does not mean every pharmacy automatically stocks a vaccine.
Moderna says MFLUSIVA is expected to be available in the United States for eligible adults during the 2026–2027 respiratory-virus season, but availability can vary.
Consumers specifically interested in receiving it may want to check before making a special trip.
That is particularly true during the first season a new vaccine reaches the market.
What Side Effects Were Reported?
According to Moderna’s patient information, common side effects reported with MFLUSIVA included reactions at the injection site, tiredness, headache, and muscle and joint pain.
The company says most side effects in the clinical trials were mild to moderate and resolved in about two days, although side effects occurred more frequently with MFLUSIVA than with the comparator flu vaccines used in those trials.
As with other vaccines, severe allergic reactions are possible.
People with a history of severe allergic reactions to vaccine ingredients or previous serious vaccine reactions should discuss those circumstances with a healthcare professional before vaccination.
Read MFLUSIVA’s patient and safety information
What if You’re Pregnant?
This is another area where consumers shouldn’t assume that an age approval automatically applies to every circumstance.
MFLUSIVA is approved beginning at age 50, but Immunize.org notes that it is not approved for use during pregnancy because of insufficient data on its use during pregnancy.
Pregnant patients should discuss their influenza vaccine options with their healthcare provider.
CDC’s broader flu guidance continues to address influenza vaccination during pregnancy, but that doesn’t make every individual flu vaccine interchangeable for every patient.
This Year’s Flu Vaccines Have Also Been Updated
MFLUSIVA isn’t the only thing that’s different about the 2026–2027 flu season.
The FDA recommended updating all three virus components included in U.S. seasonal influenza vaccines compared with the previous season.
One of those updates addresses the influenza A(H3N2) subclade K virus that circulated widely during the 2025–2026 season.
That means this year’s flu vaccine isn’t simply a repeat of last year’s formulation.
Timing Still Matters
For most adults, CDC guidance has traditionally targeted September or October as the ideal time for influenza vaccination.
Vaccination can continue later in the season while influenza viruses are circulating.
The goal is to receive protection before influenza activity becomes widespread without necessarily vaccinating so early that protection could diminish later in the season.
That makes late September and October exactly when millions of families will begin encountering these choices at pharmacies, doctor’s offices and workplace vaccination clinics.
The Bottom Line Before Your Pharmacy Visit
The simplest way to understand this year’s situation is to separate three different facts.
First: The FDA approved Moderna’s MFLUSIVA on August 5, 2026. It is the first FDA-approved mRNA seasonal influenza vaccine and is approved for adults 50 and older.
Second: Adults ages 50 through 64 received traditional approval, while the indication for people 65 and older received accelerated approval, with additional research required to confirm clinical benefit in that older population.
Third: CDC’s current 2026–2027 influenza guidance is operating under unusual legal circumstances and does not specifically incorporate the newly approved MFLUSIVA vaccine. At the same time, CDC continues to recommend annual influenza vaccination and says people should receive an appropriate FDA-licensed vaccine for their age.
For adults in their 50s and early 60s, the new vaccine represents something consumers haven’t had before: an mRNA option for seasonal influenza.
But its arrival doesn’t mean everyone over 50 suddenly needs a different flu shot.
This fall, the best question at the pharmacy may not simply be, “Can I get my flu shot?”
It may be:
“Which flu vaccines are available for someone my age, and is there a reason one makes more sense for me than another?”
That small conversation can help cut through a season in which the science, FDA approval and federal recommendation process aren’t moving in quite the usual way.
Sources
U.S. Food and Drug Administration — MFLUSIVA approval and product information
CDC — Interim Clinical Considerations for 2026–2027 Seasonal Influenza Vaccines
CDC — 2026–2027 Flu Season Information