FDA Panel Endorses Moderna's mRNA Flu Vaccine for Older Adults

An advisory panel to the Food and Drug Administration recommended approval of Moderna's mFlusiva, an experimental flu vaccine that uses messenger RNA technology to trigger immune responses against influenza.

The panel's backing clears a path for the shot's use in older Americans as the Northern Hemisphere enters flu season. Moderna developed mFlusiva to target circulating flu strains, following the company's success with its COVID-19 vaccine, which also relied on mRNA technology.

Messenger RNA vaccines instruct human cells to produce proteins that mimic viral components, prompting the immune system to develop defenses without exposing people to live or inactivated virus. Moderna has positioned mFlusiva as an alternative to traditional flu shots, which use egg-based production methods or other manufacturing approaches.

The FDA panel evaluated clinical data on mFlusiva's safety and effectiveness before issuing its recommendation. The agency's full approval process typically follows an advisory panel's endorsement, though regulators retain authority to make independent determinations.

Moderna conducted trials to demonstrate that mFlusiva generates antibody responses comparable to or exceeding those produced by conventional flu vaccines. The company focused initial development on older populations, who face elevated risks of severe flu complications.

The timing positions mFlusiva for potential deployment before peak flu transmission typically arrives in late fall and winter months. Public health officials encourage vaccination in September and October to maximize protection during high-transmission periods.

Moderna joins other vaccine manufacturers in pursuing mRNA approaches for respiratory diseases. The company has also explored mRNA candidates for respiratory syncytial virus and other pathogens using similar technology platforms.

Traditional flu vaccines require annual updates to match circulating strains. Health authorities select vaccine compositions months in advance based on surveillance data predicting which variants will predominate. The mRNA platform may eventually allow manufacturers to reformulate shots more quickly if viral evolution outpaces existing vaccine designs, though regulators would need to evaluate any modified versions separately.

The recommendation represents an expansion of mRNA vaccine applications beyond COVID-19, where Moderna and Pfizer pioneered the technology's large-scale deployment. Both companies have marketed COVID-19 shots since late 2020, accumulating data on long-term safety profiles in billions of doses administered globally.

Flu vaccination rates among Americans age 65 and older typically range from 60 to 75 percent during peak seasons, according to CDC data. Uptake varies by region and demographic factors. Introduction of mFlusiva could provide physicians another option for patients with allergies to eggs or other standard vaccine components.

The FDA typically completes its review process within weeks of receiving an advisory panel recommendation, unless regulators identify safety concerns or request additional data from manufacturers.