The FDA may approve Moderna’s mRNA flu vaccine. The larger question is whether America still intends to lead the technology that will power the next pandemic response.
On June 18, 2026, every member of the FDA's independent vaccine advisory committee — nine out of nine — voted to recommend approval of Moderna's mFlusiva, an mRNA flu vaccine for older adults. Nine voted yes, and yet the most important question isn’t whether Moderna’s flu vaccine will be approved. It’s whether the United States still intends to lead the technology that made Operation Warp Speed possible.
But the story of mRNA and influenza in the United States right now is not primarily a story about one vaccine. It is a story about whether this country will remain a serious participant in the technology that will determine the outcome of the next pandemic.
Influenza is the pandemic pathogen
This has been my conclusion for decades.
Influenza matters because it is the pandemic pathogen we know best—and the one most likely to surprise us again. Unlike many emerging infectious disease threats, influenza is not rare or exotic. It circulates continuously in birds, pigs, and humans, mutating relentlessly and periodically acquiring the ability to spread efficiently through populations with little preexisting immunity. The 1918 influenza pandemic killed an estimated 50 million people worldwide, and subsequent pandemics in 1957, 1968, and 2009 demonstrated that influenza’s capacity for global disruption remains intact. Every year, seasonal influenza causes substantial illness, hospitalization, and death, but its greatest threat lies in its evolutionary potential. We do not know when the next influenza pandemic will occur, but history suggests that it is a matter of when, not if. That reality makes investments in adaptable vaccine platforms more than a public health decision. They are part of the civilizational infrastructure that stands between human ingenuity and one of nature’s most reliable pandemic threats.
Every year, we grow most flu vaccines inside chicken eggs, the same technology that produced flu vaccines since the 1940s. Influenza mutates when it grows in eggs — a process called egg adaptation — so the vaccine that eventually results may be subtly different from the strain it was targeted against. On top of that, the strain selection for any given flu season happens months before that season starts. When the virus drifts between selection and distribution, the vaccine's effectiveness collapses. In a bad mismatch year, we are handing people a shield that does not quite fit the threat.
It's important to note that two existing alternatives — FluBlok, which uses recombinant protein technology and inset cell lines, and Flucelvax, which grows the virus in mammalian cells rather than eggs — already sidestep the egg-adaptation problem to varying degrees, and both represent genuine improvements over the traditional process but are still tied to the egg-based timetable.
mRNA solves both of these problems. Because mRNA vaccines are manufactured synthetically — no eggs involved — there is no adaptation artifact. And because the manufacturing process is fast, the lag between strain selection and vaccine delivery can shrink dramatically. Moderna has made exactly this argument: when the flu strain mutates late, an mRNA platform can respond in a way that egg-based manufacturing simply cannot.
The Phase 3 data bears this out. In a trial of nearly 41,000 adults aged 50 and older, mFlusiva was 27 percent more effective than a standard-dose flu shot — and this result came during one of the most severe flu seasons in years, when you might have expected both vaccines to underperform relative to a milder year. In the 65-and-older cohort, the immunogenicity data compared favorably to the high-dose vaccine already recommended for that age group. The VRBPAC looked at all of this, asked hard questions about the single-season data window and the limited data in frail elderly patients, and still voted unanimously in favor.
What happened in February
So, it matters that in February 2026, Dr. Vinay Prasad — then FDA's former top vaccine official, installed under HHS Secretary Robert F. Kennedy Jr. — rejected Moderna's application. Not rejected the vaccine after review. Refused to review it at all.
His stated reason was that the trial was not "adequate and well-controlled" because Moderna used a standard-dose flu shot as the comparator in the main trial rather than the high-dose vaccine recommended for seniors. There is an obvious problem with this objection: FDA scientists and career officials had previously approved that study design. Prasad issued the refusal over their objections. Moderna published the FDA's letter alongside a statement pointing out that the agency had, in their words, backtracked on prior communications and contradicted established guidance. Within a week the FDA reversed course.
But the reversal does not undo the thing that actually matters.
The signal is louder than the reversal
A pharmaceutical company making a billion-dollar, decade-long investment in vaccine development does not allocate capital based on last week's FDA policy position. It allocates based on the long range. Before February 2026, a company planning an mRNA flu program could look at the regulatory pathway and see a predictable process with established rules. After February 2026, they have to include in their model the possibility that the FDA will simply decline to engage — at any stage, for reasons that contradict the FDA's own prior guidance, driven by the anti-human political ideology of RFK Jr.
The kill shot to a pipeline is not always a formal rejection. Sometimes it is just opacity. The question "will FDA review this?" should have an unequivocal, transparent, and predictable answer.
While we were fumbling, Europe moved
On April 20, 2026, the European Commission granted full marketing authorization for mCombriax — Moderna's combined mRNA flu and COVID-19 vaccine — valid across the European Union. The European Medicines Agency's scientific committee had recommended it in February. Europe saw the data, ran a rigorous process, and issued a decision. The first combined mRNA flu vaccine is now available in Europe.
Meanwhile the US is still awaiting an FDA decision on the flu-only version.
This is a strategic divergence.
And it sits in juxtaposition to another demonstration of the power of the mRNA platform. mRESVIA, Moderna's mRNA RSV vaccine, was FDA-approved in May 2024 — the second mRNA vaccine ever approved in humans. This path-breaking technology translates across respiratory viruses. The platform is invaluable to anyone who is not an adherent to an anti-human philosophy. Accordingly, in August 2025, HHS Secretary Kennedy canceled $500 million in mRNA vaccine research contracts.
The platform is leaving
The UK has proved more hospitable. Moderna has committed over £1 billion in R&D investment through a 10-year strategic partnership with the British government, opened a manufacturing facility in Harwell capable of producing 250 million doses annually in a pandemic, and just launched a Phase 3 trial of an mRNA H5N1 vaccine as part of that partnership. When Moderna's CEO Stéphane Bancel was asked why, he said the UK was chosen because it "still believes in vaccination" — and that if anti-vaccine sentiment continues to erode US demand, the UK investment "may pay dividends."
Sanofi, the French pharmaceutical company, has made an over €1 billion in investment to build a complete end-to-end mRNA manufacturing capability in France, from plasmid production to final vial.
The European Commission launched a "Choose Europe for Life Sciences Strategy" in July 2025, explicitly identifying mRNA platforms as cornerstones of European health sovereignty and pandemic preparedness. The program includes €300 million from Horizon Europe, dedicated manufacturing capacity, and a goal of making the EU the most attractive destination for life sciences by 2030.
As RNA biologist Jeff Coller told BioPharma Dive, "The future is very bright for mRNA research in other countries."
Years before COVID, colleagues and I recognized that vaccine platforms should be viewed as strategic infrastructure rather than individual products. In a report I coauthored with colleagues from the Johns Hopkins Center for Health Security, I argued that mRNA platforms represent a "sustainable pluripotent infrastructure" that can be applied to emerging infectious disease vaccines with minimal added financial risk. The reason is precisely that the platform is not pathogen-specific. You do not build it for one virus. You build it, and then you aim it wherever the threat appears. Vaccine Platforms: State of the Field and Looming Challenges was written before COVID. We knew then what mRNA could become. We have now seen it perform. And the institutional response from the current US administration has been to attack it.
What we are actually giving away
The mRNA platform is not just about a new flu vaccine. It is the on ramp to the next Operation Warp Speed. When COVID-19 arrived, the reason a vaccine was in arms within a year was not luck. It was that Moderna, BioNTech, the NIH Vaccine Research Center, and BARDA had spent a decade building and funding and practicing on this platform. Barney Graham's two-proline substitution that locked the spike protein in the right shape. Katalin Karikó's pseudouridine modification that solved the immune activation problem. The lipid nanoparticle delivery system. None of that was improvised in 2020. It was accumulated, piece by piece through a multi-decade R&D investment.
You cannot improvise a platform when you need it. You build it during the years when you do not need it, and then it is there. If we spend the next several years delegitimizing the technology and creating regulatory uncertainty that drives companies and scientists to Europe, we will not have a warm mRNA base when Disease X arrives. We will have a government that rejected it.
The right next step is not just approval
The VRBPAC vote matters. FDA approval by August 5th would matter. But the full picture requires more.
More fundamentally, the damage done by February 2026 is not reversed by a 9-0 VRBPAC vote. The companies planning the next generation of mRNA flu vaccines, the universal influenza programs, the Disease X response platforms — they already saw February. They are already incorporating into their investment decision making the probability that something like that happens again.
The mRNA platform is arguably the most important biomedical technology developed in the last century. It was built in the United States. It has already saved millions of lives. It is now, demonstrably, being built in Europe and elsewhere while the United States government actively undermines it.
This is not a regulatory story. This is a civilizational choice.