The first mRNA flu shot is now available, but not everyone is eligible.
Moderna’s mFlusiva is the first flu vaccine in the United States to use messenger RNA technology, the same platform used in Pfizer and Moderna’s Covid shots. Scientists have long been interested in using mRNA against the flu because the vaccines can be made faster, potentially making it easier to keep up with changing flu strains.
It’s too early to predict how severe the upcoming flu season will be and the Centers for Disease Control and Prevention hasn’t started tracking cases yet. The CDC recommends getting vaccinated by the end of October.
In a late-stage clinical trial, published in the New England Journal of Medicine in May, mFlusiva was found to be about 27% more effective than a standard flu shot. The Food and Drug Administration approved mFlusiva in August for people 50 and older, clearing the way for the shot to reach pharmacies in time for this year’s flu season.
Pharmacies, however, say the new vaccine is already causing confusion among some patients about who can get it, how it compares with traditional flu shots and where people will be able to find it.
Here’s what you need to know:
Who can get the new mRNA flu shot?
The mRNA vaccine is available only for people 50 and older.
“If you have not celebrated your 50th birthday, this vaccine should be of no interest to you,” said Emlah Tubuo, an independent pharmacist in Ohio.
The FDA granted traditional approval for adults 50 to 64 and accelerated approval for people 65 and older, with Moderna required to conduct another trial in that age group. People who do not want the mRNA vaccine can still get a traditional flu shot.
The additional trial in adults 65 and older stems from a controversy that nearly derailed the vaccine’s approval.
In a large clinical trial, Moderna compared mFlusiva with a standard-dose flu shot in people 65 and older, even though the CDC recommends a high-dose flu shot for that age group.
The FDA initially refused to review Moderna’s application over that issue before reversing course and agreeing to a post-approval clinical trial. In June, the FDA’s independent vaccine advisory panel unanimously recommended the approval of the vaccine for older adults.
People younger than 50 won’t be able to get mFlusiva this flu season. Instead, they can get one of the other flu vaccines approved for their age group.
How is the mRNA shot different from a traditional flu shot?
The biggest difference is how the vaccines teach the immune system to recognize influenza.
Most traditional flu shots use a deactivated version of the virus — often grown in eggs — to teach the immune system how to fight it.
MFlusiva uses a small snippet of genetic code to train the body to recognize and fight the flu virus. The mRNA from the vaccine is then broken down and does not remain in the body.
“It’s like a temporary instruction to your immune system to alert your body’s natural defense to recognize influenza,” Tubuo said. It takes about two weeks after vaccination to build protection.
One point of confusion among patients, according to Brigid Groves, a pharmacist with the American Pharmacists Association, is whether mFlusiva also protects against Covid. It doesn’t. The vaccine only targets the flu and is separate from Moderna’s combination Covid and flu vaccine, which was approved by the European Union in April.
Like the traditional seasonal flu vaccines this year, Moderna’s shot is a trivalent vaccine, targeting two influenza A strains and one influenza B strain.
Another difference is that Moderna’s vaccine can be made faster, said Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center.
Scientists typically have to choose which flu strains to target months before flu season begins, leaving time to manufacture millions of doses. Traditional flu vaccines can take about six months to produce, while Moderna says mFlusiva can be made in two to three months. That shorter timeline, Schaffner said, allows them to wait longer before choosing which strains to target, giving them a better idea of which ones are likely to circulate.
Is the mRNA shot safe and effective?
Published data from a Phase 3 clinical trial suggests mFlusiva should work better than a standard-dose flu shot.More than 40,000 adults 50 and older across 11 countries, including the United States, participated in the trial. The trial found mFlusiva was about 27% more effective than the standard-dose vaccine at preventing laboratory-confirmed illness.
FDA reviewers did not identify any serious safety problems with the vaccine.
Rates of side effects — such as injection-site pain, fatigue and headaches — were more common in the mFlusiva group but still mild to moderate.
Schaffner said the higher rate of side effects may be “a reflection of the vigor with which the immune system responds to the vaccine.”
Will insurance cover mFlusiva?
MFlusiva is reaching pharmacies without a formal recommendation from the CDC or its vaccine advisory committee, a step typically needed to require insurers to cover vaccines for free.
A spokesperson for AHIP, a trade group for health insurers, said it expects most private insurers will cover the vaccine.
Dorit Reiss, a vaccine policy expert at University of California Law San Francisco, said Medicare is required to fully cover the cost of FDA-approved seasonal flu shots.
Reiss said it remains unclear, however, how widely Medicaid will cover the new shot this season, as the program typically requires a formal recommendation from the CDC’s vaccine advisory committee.
According to the Centers for Medicare and Medicaid Services, mFlusiva has a price tag of around $171 per dose without insurance. Depending on the pharmacy, the cost could be as low as $154, according to GoodRx.
Where can people get it?
As with any vaccines, whether you can get the shot right away will depend on your local pharmacy’s current stock and delivery schedule.
In a statement, a Moderna spokesperson said the company has begun shipping doses of mFlusiva across the U.S.
Amy Thibault, a CVS Health spokesperson, said mFlusiva is available at its U.S. pharmacies. A Walgreens spokesperson said it expects to begin receiving shipments of the vaccine any day now, although it’ll be available to patients in “limited quantities” this season.
Tubuo, the Ohio pharmacist, said that demand for mFlusiva is currently low, noting that it is still early in the season and most people do not seek vaccination until October.
