The Food and Drug Administration (FDA) has approved Moderna's mFlusiva, a new mRNA-based flu vaccine for adults aged 50 and older. This marks the first flu vaccine to utilize the mRNA technology that was central to the development of COVID-19 vaccines.
Moderna announced that the new vaccine is expected to be available in select retail locations soon, ahead of the fall vaccination season. While multiple flu vaccine options currently exist in the U.S., including some specifically recommended for individuals 65 and older, influenza still causes tens of thousands of deaths annually, with older adults being particularly vulnerable.
Flu vaccines require annual updates to effectively target circulating strains of the virus. Vaccines developed with mRNA technology are noted for their rapid manufacturing process. Experts suggest this advantage could be crucial if the influenza virus mutates unexpectedly, necessitating the swift development of new vaccine doses.
According to Moderna, the FDA granted full approval for mFlusiva's use in individuals aged 50 to 64. This decision was based on a study involving 40,000 participants, which indicated a 27% reduction in flu cases among those who received the new vaccine compared to those who received a different common flu vaccine.
For individuals aged 65 and older, the FDA granted accelerated approval for mFlusiva. This designation, based on a smaller study demonstrating a strong immune response compared to an existing high-dose vaccine for seniors, will be followed by an additional confirmatory study.
Moderna reported that the vaccine did not show significant safety issues. Temporary reactions, such as injection site pain, fever, headache, fatigue, and body aches, were observed and occurred slightly more frequently than with existing flu shots.
The FDA's approval followed a notable public disagreement earlier in the year. A high-ranking FDA official initially blocked the company's application, a move that occurred amidst heightened vaccine scrutiny at the agency. However, the FDA later reversed its decision after Moderna publicly challenged the ruling. In June, a panel of independent advisors to the FDA unanimously recommended the vaccine's approval.