Moderna notched a hard-fought FDA win earlier this month when the agency approved mFlusiva for adults aged 50 and older, making it the first approved mRNA flu vaccine in the U.S. The agency used the accelerated approval pathway for those 65 and older, meaning continued approval for the older group could depend on a confirmatory trial.
The approval came after months of back-and-forth with the agency, which issued a refusal-to-file letter in February and initially declined to review Moderna’s application. But snagging the FDA OK will likely be just the first hurdle Moderna faces as it brings the vaccine to market.
In a phase 3 trial of adults 50 and above, mFlusiva demonstrated 26.6% relative vaccine efficacy compared with a standard-dose flu jab. Its mRNA platform can produce vax doses faster than conventional vaccines. Still, the new shot carries a lot of baggage, including mRNA skepticism, Moderna’s past tussles with the FDA and a political environment that’s often unfriendly to vaccines in general.
However, “the big plus or minus could be” the timing of annual flu vaccine strain selection, according to Myles Minter, a partner and biotech research analyst at William Blair.
Currently, annual flu vaccine strains are chosen six to nine months ahead of flu season. With mRNA vaccines’ faster production, flu vaccine strain selection could theoretically be delayed until two months before flu season, boosting the odds of pinpointing that season’s circulating strains.
“You could theoretically make multiple different vaccines throughout one season if you wanted to,” Minter said.
From there, vaccine efficacy would also theoretically increase because of the closer strain match, he said. Moderna President Stephen Hoge touted this edge for mFlusiva in an investor relations video on the company’s website.
Then again, that advantage might be moot. If the WHO and FDA don’t adjust their current strain selection process, “then it doesn't matter what Moderna does and how fast they can make a vaccine because the recommendation for the strain is uniform and you have to make it against that,” Minter said. “It basically takes away that advantage.”
To leverage that edge, Moderna will need to push for a “framework shift” among global regulators. Those authorities would need to believe “there is an advantage in doing so to protect the people better against seasonal influenza,” according to Minter.
Navigating flu market challenges
Even without the benefit of later strain selection, mFlusiva outperformed a standard-dose flu vaccine in a phase 3 trial. But Moderna still has other hurdles to work around. As with any newly launched vaccine, market traction will largely hinge on regulatory recommendations and list versus net price. Moderna also faces flu-specific challenges, like the fact that consumers don’t typically get to choose which vaccine they get.
Although Moderna expects mFlusiva to reach select retailers in a few weeks, analysts don’t expect it to generate meaningful revenue in the short term because the company already missed this season’s contracting cycle. But mFlusiva revenue could pick up down the road.
“In terms of changing the top-line revenue trajectory for the company, you're probably going to see an impact of this U.S. FDA flu vaccine approval starting in 2027,” Minter said. “Longer term, I think the value of this product is several fold.”
The firm projects mFlusiva revenue will hit $131 million in 2027 and then cross the blockbuster threshold with peak sales of $1.1 billion annually, about one-fifth of the current market, he said.
Regulatory and market hurdles aside, infectious disease experts view mFlusiva as a “game changer,” Minter said.
“If there's good adoption, I think it'll change the fundamental aspects of how we vaccinate against seasonal influenza,” he said.
More precise and nimble strain selection could boost flu vaccine efficacy, which could, in turn, increase vaccination rates that remain low.
“If we can close that gap and become more accurate at doing it, we should drive that effectiveness up. And if it's a more effective product … in theory, that uptake number would go up,” Minter said.
mFlusiva’s approval could also restart regulatory momentum for Moderna’s flu and COVID-19 combo vaccine in the U.S. Earlier this year, European regulators approved the combo shot, but the FDA hit the brakes on its review and asked Moderna for additional phase 3 efficacy data on the flu component.
“Now, the question is: Does this approval in flu alone open up the regulatory door again?” Minter said. “That could be something interesting.
