FDA Approves First mRNA Flu Vaccine for Older Adults

In the underlying clinical study of more than 40,000 adults aged 50 and older, mFlusiva was tested during the 2024/25 respiratory virus season. According to the manufacturer, the new vaccine was approximately 27 percent more effective than standard flu vaccines. The study is considered one of the largest comparative investigations to date between classic and mRNA-based flu vaccines and is said to have formed the basis for the FDA approval.

Study with more than 40,000 participants

The decision marks another milestone for mRNA technology, which became known worldwide during the coronavirus pandemic. Moderna has been researching for years how to apply the platform principle to other respiratory illnesses such as seasonal flu and Respiratory Syncytial Virus (RSV). Industry observers see the approval as confirmation that mRNA vaccines can establish themselves beyond Covid-19.

The market launch of mFlusiva is planned for the upcoming flu season in the United States. Moderna stated that the vaccine would initially be available for adults aged 50 and older, as this group has the highest risk of hospitalizations and deaths from influenza viruses. The costs and exact timing of availability were initially not provided in detail.

Political environment and potential impact

The FDA approval comes in a politically charged environment. Health Secretary Robert F. Kennedy Jr. has repeatedly criticized mRNA vaccines in the past and has threatened budget cuts for corresponding research programs. It initially remained unclear how the new approval would affect ongoing discussions about government vaccine policy.

Experts see mFlusiva primarily as progress for older people whose immune systems respond more weakly to conventional vaccines. mRNA vaccines can be adapted more quickly to new virus variants than classic vaccines, which are produced in chicken eggs or cell cultures. This flexibility is considered one of the main advantages of the technology.

Significance for older patients and international agencies

The approval now granted applies exclusively to seasonal flu. Further areas of application must be examined in separate studies. Moderna had already announced the development of combination vaccines against flu and RSV but is still in earlier phases of clinical testing.

International health authorities are likely to closely follow the FDA's decision. The European Medicines Agency (EMA) had already relied on U.S. data on mRNA technology in earlier proceedings. Approval in the EU, however, would be a separate procedure that would still need to be initiated. Observers do not expect a corresponding decision before the second half of next year.

Independent professional associations welcomed the FDA approval as a positive step. The combination of an established mRNA platform and a large study in an at-risk group provides a solid basis for use in older adults. At the same time, experts pointed out that classic flu vaccines continue to play an important role and that mRNA vaccines should complement rather than replace them.