Moderna announced that the FDA has approved its trivalent mRNA-1010 flu vaccine (mFLUSIVA) for use in all adults aged 50 years or older. It is the first mRNA-based flu vaccine approved by the FDA in the USA.

Moderna received traditional approval in adults aged 50 to 64 years. It also received accelerated approval for those individuals 65 and older, but Moderna will also need to gather data from a postmarketing effectiveness study for that population.

Moderna also said that the vaccine will be available for the 2026-27 flu season.

Moderna mRNA flu vaccine study results

As I wrote previously, the clinical trial results were first published on 7 May 2026 in the New England Journal of Medicine. Isabel Leroux-Roels, Ghent University, Belgium, and colleagues examined the results from a phase III trial that randomly assigned 40,703 adults 50 and older (mean age 64, 57% women) to receive Moderna’s trivalent mRNA-1010 flu vaccine (37.5 μg, which includes 12.5 μg each of A/H1N1, A/H3N2, and B/Victoria) or a licensed standard-dose trivalent or quadrivalent flu vaccine comparator.

Flu illness in both groups was confirmed by reverse transcriptase-polymerase chain reaction testing.

Here are the key data that were presented to the FDA:

1. Influenza A or B illness was observed in 2% of participants who received the trivalent mRNA-1010 vaccine, compared with 2.8% of those who received approved standard-dose vaccines through the end of the flu season. The mRNA-1010 vaccine had a higher relative vaccine effectiveness of 26.6% compared to the standard flu vaccines. (Note: relative vaccine effectiveness is the difference in effectiveness between the mRNA-1010 vaccine and the standard, currently available vaccines. Thus, the mRNA-1010 is 26.6% more effective than the standard vaccines.)
2. Among the more than 19,000 adults aged 65 and older in the clinical trial, a population more susceptible to flu complications, the relative vaccine effectiveness of mRNA-1010 was 27.4% compared to the standard flu vaccines.
3. Medically-attended influenza-associated outcomes across all healthcare settings occurred in 80 participants in the mRNA-1010 group and 120 in the standard-dose comparator group, for a relative vaccine effectiveness of 33.7%.
4. Among the 64 participants who sought higher-level care, hospitalization, emergency department, or urgent care encounters occurred in 22 recipients of mRNA-1010 and 42 recipients of the standard-dose comparator, which indicated a relative vaccine effectiveness of 47.9%.
5. The mRNA-1010 vaccine candidate had a substantially higher risk of solicited adverse events compared with standard vaccines, including injection-site pain (65.8% vs 29.8%), fatigue (45.1% vs 20.3%), headache (37.8% vs 18.0%), and myalgia (35.4% vs 11.6%). Most reactions were mild to moderate and transient. Serious adverse events were “infrequent and similar in the two groups.”
6. Overall, 2.2% of mRNA-1010 recipients experienced adverse events (only three were considered vaccine-related) versus 1.9% in the comparator group (only two were vaccine-related).

Approval in the older group was based on a separate phase III study that showed mRNA-1010 led to greater immunogenicity compared with the current high-dose flu vaccine in those 65 or older.

Summary

Ronald Nahass, MD, president of the Infectious Diseases Society of America, said that the approval

…is welcome news” (that) “highlights the tremendous potential of mRNA vaccine technology.

Unlike conventional manufacturing, the mRNA platform allows for streamlined development and rapid responses to emerging mutations in viruses. Demonstrating the success of mRNA for influenza opens the door to broader applications, accelerating our ability to create safe and targeted vaccines for a wider range of preventable diseases.

This is all good news, considering the FDA refused to review Moderna’s vaccine application in February 2026. Then the FDA reversed itself a few days later and stated that it would review the application.

This approval occurred despite HHS Secretary Robert F Kennedy Jr’s longstanding opposition to mRNA technology for vaccines.

I have written previously that the mRNA technology for vaccines is incredibly safe and does not do anything that anti-vaccine activists have claimed, like changing your DNA.

The mRNA technology allows us to quickly develop new flu vaccines in response to new mutations in the influenza viruses. This could reduce the risk of a flu pandemic in the future.

I know that this vaccine will scare off many people, but it is extraordinarily safe and much more effective than current flu vaccines. I can’t wait to get it.

Citations

• Leroux-Roels I, Huang G, Ferguson M, Kohli A, Clark R, Bickel M, Soens M, Du E, Pucci A, Hicks B, Eschen C, Das R, Wilson E; Fluent Trial Investigators. Efficacy and Safety of an mRNA Seasonal Influenza Vaccine in Adults. N Engl J Med. 2026 May 7;394(18):1803-1813. doi: 10.1056/NEJMoa2516491. PMID: 42090792.
• Soens M, Ananworanich J, Hicks B, Lucas KJ, Cardona J, Sher L, Livermore G, Schaefers K, Henry C, Choi A, Avanesov A, Chen R, Du E, Pucci A, Das R, Miller J, Nachbagauer R. A phase 3 randomized safety and immunogenicity trial of mRNA-1010 seasonal influenza vaccine in adults. Vaccine. 2025 Mar 19;50:126847. doi: 10.1016/j.vaccine.2025.126847. Epub 2025 Feb 7. PMID: 39919447.

Help the Skeptical Raptor keep writing about vaccines

There are four ways you can help contribute to keeping this website running at full speed:

1. GoFundMe.
2. Subscribing via Patreon.
3. Buying your favorite stuff on Amazon.
4. Sharing this article on Social Media.