The US Food and Drug Administration (FDA) approved Moderna’s influenza vaccine for older adults on Wednesday. The vaccine, which will be marketed as mFlusiva, is the first licensed flu shot produced using messenger RNA (mRNA) technology.
The FDA issued a standard approval for the vaccine for use in adults aged 50 to 64, while an accelerated approval was granted for adults 65 years and older.
27% reduction
Lower likelihood of contracting test-confirmed influenza in adults aged 50-64 compared to the standard-dose comparator.
In the 50 to 64 age group, trial participants receiving the Moderna vaccine were 27% less likely to contract test-confirmed influenza compared to those who received the standard-dose comparator. While safety profiles between the mRNA vaccine and the standard-dose comparator were similar, more side effects were reported in the mRNA vaccine group; most were described as mild and lasting one to two days.
The Phase 3 clinical trial for the vaccine was conducted across 11 countries. Moderna expects to have doses of the vaccine available before the upcoming flu season.
Flu is a challenge, and mFLUSIVA provides an important new option for America’s seniors.
— Moderna CEO Stéphane Bancel
Regulatory background and trial requirements
The approval follows a series of regulatory events. In February, the FDA’s head of biologics at the time, Vinay Prasad, issued a refusal-to-file notice to Moderna because the agency would not review the vaccine based on the available data package. This decision was reversed a week after Moderna disclosed the FDA decision and its own concern. Vinay Prasad left the FDA at the end of April.
In June, an expert panel advising the FDA on vaccines voted unanimously that the benefits of the vaccine outweighed any risks. As part of the approval for those aged 65 and older, Moderna has agreed to conduct a Phase 4 post-licensure trial to gather more effectiveness data, specifically comparing mFlusiva to existing high-dose or adjuvanted vaccines.
Global expansion and manufacturing
MFlusiva is Moderna’s fourth vaccine to enter the US market. The vaccine has been accepted for regulatory review in the European Union, Canada, and Australia, with plans to submit for review in additional countries later this year.
MRNA vaccines can be manufactured significantly faster than traditional egg-based or cell-based vaccines, which allows for potential updates to targeted strains closer to flu season.
Updates
The mFlusiva vaccine is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season. Separately, US Health Secretary Robert F. Kennedy Jr. has expressed disapproval of the mRNA platform, noting that funding should move toward “safer, broader vaccine platforms that remain effective even as viruses mutate.” Additionally, reports indicate the US Department of Health and Human Services canceled at least $500 million of federally funded mRNA vaccine development last year.
The mFlusiva vaccine is expected to be available for individuals aged 50 and older for the 2026-2027 respiratory illness season. Meanwhile, US Health Secretary Robert F. Kennedy Jr. has expressed disapproval of the mRNA platform, stating that funding should go toward “safer, broader vaccine platforms that remain effective even as viruses mutate.” Additionally, reports indicate the US Department of Health and Human Services canceled at least $500 million of federally funded mRNA vaccine development last year.
The mFlusiva vaccine is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season. Following an initial refusal to review the application, the FDA reversed its position after what Moderna described as a 'constructive' meeting. Meanwhile, US Health Secretary Robert F. Kennedy Jr. has expressed disapproval of the mRNA platform and requested a reassessment of approval processes for certain vaccines, including influenza.
The mFlusiva vaccine is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season. Meanwhile, US Health Secretary Robert F. Kennedy Jr. has expressed disapproval of the mRNA platform, with the FDA requesting a reassessment of approval processes for certain vaccines, including influenza, under his leadership. Additionally, the FDA's decision to review the application was reportedly reversed following a 'constructive' meeting with Moderna after an initial refusal.
The FDA initially refused to review the vaccine application before reversing its position following a meeting that Moderna described as 'constructive'. Amidst this process, US Health Secretary Robert F. Kennedy Jr. expressed disapproval of the mRNA platform, and under his leadership, the FDA has requested a reassessment of approval processes for certain vaccines, including influenza. Additionally, the mFlusiva vaccine is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season.
The FDA initially refused to review Moderna's influenza vaccine application before reversing its position following what Moderna described as a 'constructive' meeting. Additionally, the mFlusiva vaccine is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season. While Phase 3 clinical trials involving 40,805 adults showed the vaccine was superior to standard-dose vaccines for preventing influenza-like illness in those over 50, researchers noted that solicited adverse events like injection-site pain and fatigue were more frequent than with current vaccines, though most were reported as mild to moderate and transient.
The FDA initially refused to review Moderna's application before reversing its decision following what the company described as a 'constructive' meeting. Meanwhile, US Health Secretary Robert F. Kennedy Jr. has expressed disapproval of the mRNA platform, prompting the FDA to request a reassessment of approval processes for certain vaccines, including influenza. Additionally, mFlusiva is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season.
The FDA initially refused to review Moderna's influenza vaccine application before reversing its position following a meeting described by the company as 'constructive'. Additionally, the mFlusiva vaccine, also known as mRNA-1010, is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season. While Moderna's Phase 3 clinical trials involving 40,805 adults showed the vaccine was superior to standard-dose versions in preventing influenza-like illness in older adults, researchers noted that solicited adverse events such as injection-site pain and fatigue were more frequent than with current vaccines.
The FDA initially refused to review the vaccine application before reversing its position following what Moderna described as a 'constructive' meeting. Additionally, the mFlusiva vaccine is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season.
The FDA initially refused to review the vaccine's application before reversing its decision following what Moderna described as a 'constructive' meeting. Furthermore, the mFlusiva vaccine, also known as mRNA-1010, is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season.
The FDA initially refused to review Moderna's influenza vaccine application before reversing its position following what the company described as a 'constructive' meeting. While the vaccine is expected to be available for the 2026-2027 respiratory illness season, US Health Secretary Robert F. Kennedy Jr. has expressed disapproval of the mRNA platform and requested a reassessment of approval processes for certain vaccines including influenza. Additionally, Moderna noted that mFlusiva can reduce the production process to two to three months, compared to approximately six months for traditional vaccines.
The FDA initially refused to review Moderna's application before reversing its decision following what the company described as a 'constructive' meeting. Meanwhile, US Health Secretary Robert F. Kennedy Jr. has expressed disapproval of the mRNA platform, and under his leadership, the FDA has requested a reassessment of approval processes for certain vaccines, including influenza. Additionally, mFlusiva is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season.
The FDA's decision to review the vaccine application was initially a refusal, but the agency reversed its position following what Moderna described as a 'constructive' meeting. Additionally, the mFlusiva vaccine, also known as mRNA-1010, is expected to be available for individuals aged 50 and older during the 2026-2027 respiratory illness season. Moderna noted that its production process can be reduced to two to three months, compared to the approximately six months required for traditional vaccines.
The FDA's decision to review the application follows an initial refusal that was later reversed after a 'constructive' meeting with Moderna. While the vaccine is intended for adults aged 50 and older, clinical trials for the 50-64 age group included approximately 40,000 participants. Additionally, Moderna noted that the production process for mFlusiva could be reduced to two to three months, compared to the approximately six months required for traditional vaccines.
While the FDA approved mFlusiva for adults 50 and older, the US Department of Health and Human Services canceled at least $500 million in federally funded mRNA vaccine development last year, and Health Secretary Robert F. Kennedy Jr.—who has criticized the mRNA platform and called its use for flu vaccines misleading—has since requested a reassessment of vaccine approval processes, sparking accusations from experts that his actions undermine scientific consensus and promote vaccine skepticism.
The mFlusiva vaccine, approved for adults 50 and older, is now expected to be available in U.S. pharmacies in the coming weeks, coinciding with the start of the 2026–2027 flu season — a timeline confirmed by Moderna, though its cost remains unclear; this follows the FDA’s reversal of its initial refusal to review the application, which critics linked to Health Secretary Robert F. Kennedy Jr.’s push to cancel $500 million in mRNA funding and his request to reassess vaccine approvals, actions opposed by experts who called his claims about mRNA vaccine failure 'phony and false.'
