First mRNA Flu Vaccine mFlusiva Now Available for Older Adults

The debut of Moderna's mFlusiva marks a significant milestone in influenza vaccination, as it becomes the first flu shot in the United States to utilize mRNA technology. This advancement follows the success of mRNA vaccines in combating Covid-19. Doses of mFlusiva are now available at CVS locations, with Walgreens expecting shipments imminently.

Eligibility and Availability

The U.S. Food and Drug Administration (FDA) approved mFlusiva for individuals aged 50 and older. Traditional approval covers adults aged 50 to 64, while those 65 and older received accelerated approval contingent on further clinical trials. Emlah Tubuo, an independent pharmacist, emphasized that the mRNA vaccine is exclusively for those over 50. Those under 50 can still receive traditional flu vaccines.

Currently, pharmacies report some confusion among patients about the new vaccine's availability and its differences from conventional flu shots. The Centers for Disease Control and Prevention (CDC) recommends getting vaccinated by the end of October, although it has yet to start tracking this season's flu cases.

How mFlusiva Differs from Traditional Flu Shots

Unlike conventional flu vaccines that use deactivated viruses, often grown in eggs, mFlusiva employs a small piece of genetic code to trigger an immune response. This mRNA is a temporary instruction for the immune system, which is broken down and does not stay in the body. Dr. William Schaffner from Vanderbilt University Medical Center highlights that this method allows for faster vaccine production, taking only two to three months compared to the six months needed for traditional vaccines.

Moderna's mRNA flu shot is a trivalent vaccine, targeting two influenza A strains and one influenza B strain, similar to this year's traditional flu vaccines. However, mFlusiva does not protect against Covid-19, a point of confusion for some patients as noted by Brigid Groves of the American Pharmacists Association. Moderna's combined Covid and flu vaccine has been approved in the European Union but is separate from mFlusiva.

Effectiveness and Safety

In a late-stage clinical trial, mFlusiva demonstrated approximately 27% greater effectiveness than standard flu shots, according to research published in the New England Journal of Medicine. The FDA's independent vaccine advisory panel had unanimously recommended its approval for older adults, despite initial controversy over trial comparisons with standard-dose flu shots instead of high-dose ones recommended for seniors.

The CDC has not yet provided predictions for the upcoming flu season's severity. However, the introduction of mRNA technology in flu vaccines represents a potential shift in how quickly and accurately vaccines can respond to evolving influenza strains.