Moderna's flu-COVID combo shot will test RFK Jr.'s vaccine regulators

Why it matters: The company this week reported positive late-stage safety and efficacy results for a flu shot called mRNA-1010 that would provide the basis for the combo jab.

• That poses a quandary for regulators, who could treat it like another seasonal flu shot for the general population or apply heightened scrutiny and require additional studies, the way they've done for new COVID boosters.

What they're saying: Moderna indicated it would cover its bets and pursue a dual track for approval after showing the flu shot jab was 26.6% more effective than a standard-dose flu vaccine in adults 50 and older.

• "We will engage with regulators on next steps, both as a potential standalone flu product and for ... our flu/COVID combination vaccine candidate," a Moderna spokesperson said in an email.

The intrigue: Food and Drug Administration commissioner Marty Makary and his top vaccine regulator, Vinay Prasad, have said flu shots should be widely recommended for all age groups. But they've limited COVID vaccine to certain age groups or high-risk individuals.

• Top Health and Human Services officials have cast serious suspicions on mRNA platforms like Moderna's; Prasad has even suggested COVID vaccine risks may outweigh benefits in low-risk populations, Endpoints reported.
• Moderna has already run afoul of the new vaccine regime. HHS in May canceled a nearly $600 million award to the company to develop an mRNA vaccine for bird flu in humans, killing one of the Biden administration's final pandemic preparedness efforts.

An HHS spokeperson said Makary and Prasad raised serious safety concerns around the risks of heart inflammation in connection with certain COVID vaccines. "We will not ignore these risks and will ensure that the gold standard of science is used for any decisions," the spokesperson said.

• Makary has previously said that the flu vaccines have been tried and tested for over 80 years while the COVID vaccine has been around for four and underwent minimal testing.

Zoom in: Financial analysts say the Moderna combo jab will yield important clues about how the FDA will handle such vaccines.

• Wall Street is less interested in the flu shot alone than the combination vaccine and how it ultimately gets treated by regulators, Mani Foroohar of Leerink Partners told Axios.
• "Will this combo be a real opportunity? How will that opportunity play out in a less forgiving regulatory environment?" he said.

• "And how will that play out in an environment where you have certainly senior leadership at HHS, plausibly at [the Centers for Disease Control and Prevention] ... which is quite skeptical on the value and differentiation of mRNA vaccines writ large?"

Between the lines: Analysts said they expect both products will be available for the 2027 respiratory illness season.

• "That said, we acknowledge ongoing vaccine policy-related uncertainty via HHS/[the Advisory Committee on Immunization Practices]," Goldman Sachs wrote in a note.
• Earlier this year, the FDA stipulated it would require additional placebo-controlled studies before it approves mRNA vaccines in younger, healthier individuals.
• "This is specifically written for COVID-19 vaccines, but it remains to be seen how far-reaching to other vaccine targets this guidance framework will be," William Blair wrote in an analyst note.

What to watch: This is not just a Washington parlor game. Moderna's facing headwinds after slashing its projected sales earlier this year. It's also facing uncertainty around the future of its closely watched cytomegalovirus, or CMV, vaccine.

• The company also faces an intellectual property challenge around the underpinnings of its vaccine technology that has potentially "existential" implications, said Foroohar.

Editor's note: The story has been updated with HHS comment.