For Moderna’s Greenlit mRNA Flu Vaccine, Payoff Is a Ways Off

Sudden high fever? Chills? Muscle or body aches? Tiredness, dry coughing, sore throat, a headache? You might have the flu. And Moderna might have its next customer.

The company clinched a hard-won victory after the US Food and Drug Administration approved the use of its mRNA flu vaccine in adults aged 50 and up. All it took was an at-times contentious, seven-month-long regulatory process. Now, Moderna is set up to prove whether its mRNA-based portfolio will become more than a pandemic-era, one-trick financial pony.

The Need for Approval

What’s so great about mFlusiva? Like Moderna’s mRNA-based COVID-19 vaccines, it delivers instructions straight to your body’s cells on how to make a harmless viral protein that can be used to train your immune system to attack viruses. Because they use a synthetic genetic code, mRNA vaccines can be updated quickly to combat variant strains, unlike traditional vaccines, which take weeks to grow in eggs or cell cultures. 

Before this week’s approval, which arrived late Wednesday, mFlusiva had to contend with its own fight. In February, Vinay Prasad, then the head of the FDA’s vaccine program, unilaterally blocked Moderna’s application over the objection of agency scientists before backing off a week later on the condition of a new study for people 65 and older. The FDA’s sign-off was based on a trial involving more than 40,000 adults 50 and up that found the shot 26.6% more effective than a standard flu vaccine. Approval in hand, mFlusiva is now positioned to compete with traditional flu vaccines from AstraZeneca, CSL, GSK, Sanofi and Seqirus in a market where tens of millions of annual vaccines represent billions in annual sales. However, Moderna will have to wait at least a year for a meaningful payoff:

• The company says it expects to have mFlusiva ready for the upcoming 2026-2027 flu season, which runs from roughly October to May.
• It’s not as easy as being ready. Seasonal vaccine sales rely on advance commercial contracting with healthcare providers, pharmacies and distributors, which is why Wall Street doesn’t think Moderna will make any meaningful mFlusiva sales until the 2027-28 flu season. In fact, shares of the pharma giant fell 4.26% on Thursday.

Pipeline Promise: Moderna’s stock is up 74.5% in 2026, and the optimist’s case rests on treatments in the pipeline like a combination therapy for skin cancer in partnership with Merck that has performed well in studies. Meanwhile, the European Union approved its first-of-its-kind COVID and flu combination vaccine in April.