FDA Panel Backs Moderna mRNA Flu Vaccine For Older Adults
An FDA advisory panel unanimously concluded Thursday that Moderna's mRNA seasonal flu vaccine candidate, mFlusiva, has benefits that outweigh risks for adults 50 and older.[1]
The panel's vote moves Moderna closer to seeking full FDA approval for people 50-64 and an emergency authorization for those 65 and older ahead of the 2026-27 flu season.[1] A 40,000-person trial in adults 50 and up found roughly a 27% reduction in influenza cases versus a standard-dose vaccine, and Moderna plans a post-approval study enrolling about 400,000 seniors over two seasons.[1]
On February 11, 2026, the FDA issued a refuse-to-file letter saying Moderna's pivotal phase 3 trial was not adequate and well-controlled. FDA officials faulted the study because it compared mFlusiva with a standard-dose vaccine rather than the best-available senior formulations.
Moderna revised its application to pursue full approval for ages 50-64 and accelerated approval for those 65 and older. The FDA accepted the revised filing on February 18, 2026 and set an August 5, 2026 decision target.
Some experts and patient advocates say the trial's lack of comparison with high-dose or adjuvanted senior vaccines leaves unanswered questions about protection for the oldest adults. During the 2024-2025 flu season the CDC estimated 710,000 flu-related hospitalizations and 45,000 deaths, with adults 65 and older accounting for 71% of deaths, highlighting the stakes for senior protection.
The mainstream summary does not mention that during the 2024-2025 flu season, adults aged 65 and older accounted for 57% of hospitalizations and a staggering 71% of deaths, underscoring the critical need for effective vaccination strategies for this demographic. While the summary highlights the FDA panel's support for Moderna's mRNA vaccine, it overlooks the concerns raised by experts regarding the trial's lack of comparison with high-dose or adjuvanted senior vaccines, which are already known to offer better protection for older adults. This raises questions about the adequacy of mFlusiva's efficacy in the most vulnerable population, particularly given that interim estimates for the 2025-2026 flu season show vaccine effectiveness for adults 65 and older at only around 30-31% against hospitalization, which is notably lower than the overall effectiveness reported for younger adults.[2]
Additionally, while the mainstream account frames the FDA's previous refusal-to-file letter as a setback for Moderna, it does not delve into the implications of the FDA's critique that the pivotal trial was inadequate because it did not compare mFlusiva against the best available senior formulations. This detail suggests a significant gap in understanding how well the new vaccine might perform relative to existing alternatives, a point that has been echoed by commentators who question whether the reported reduction in flu-like illness justifies the potential increase in adverse reactions.[3]
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📊 Relevant Data
During the 2024-2025 flu season, CDC estimated 710,000 flu-related hospitalizations and 45,000 deaths in the US, with adults 65+ accounting for 57% of hospitalizations and 71% of deaths while adults 50-64 accounted for 20% of hospitalizations and 21% of deaths.
2024–2025 Influenza Season Summary: Severity, Disease Burden, and Vaccination Impact — CDC
Interim estimates for the 2025-2026 flu season showed vaccine effectiveness of 22-34% against influenza-associated outpatient visits and 30% against hospitalization among US adults aged 18+, with lower estimates (around 30-31%) specifically for adults 65+.
Interim Estimates of 2025–26 Seasonal Influenza Vaccine Effectiveness — CDC MMWR
CDC projects up to 154 million doses of seasonal flu vaccine will be supplied for the 2025-2026 season, with approximately 135.6 million doses distributed as of March 2026.
2025–2026 Flu Season — CDC
📌 Key Facts
- On Thursday, June 18, 2026, an FDA advisory panel unanimously said mFlusiva’s benefits outweigh risks in adults 50 and older.
- Moderna seeks full FDA approval for ages 50-64 and emergency authorization for those 65+ ahead of the 2026-27 flu season.
- A 40,000-person study in adults 50+ found roughly a 27% reduction in flu cases versus a standard-dose vaccine.
- A planned post-approval study will enroll about 400,000 people 65+ over two seasons, half receiving mFlusiva and half existing senior flu shots.
- mFlusiva is the first seasonal flu vaccine candidate to use mRNA technology already employed in COVID-19 vaccines.
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