WASHINGTON: A new type of influenza vaccine moved a significant step closer to the U.S. market after an independent panel of advisers to the Food and Drug Administration (FDA) unanimously recommended approval of Moderna's mRNA-based flu vaccine for older adults.
According to an Associated Press (AP) report, the recommendation could pave the way for the first influenza vaccine developed using messenger RNA (mRNA) technology, the same platform that played a pivotal role in the rapid development of COVID-19 vaccines during the pandemic.
Moderna is seeking full FDA approval for the vaccine, known as mFluSVA, for adults aged 50 to 64 years, along with authorisation for adults aged 65 years and older while the company conducts additional studies in the senior population.
The FDA's independent advisory committee reviewed the company's clinical data and concluded that the benefits of the vaccine appear to outweigh its risks in both age groups. The FDA is expected to make a final decision on the application by early August, ahead of the upcoming winter influenza season.
Influenza remains a major public health concern in the United States, causing tens of thousands of deaths each year. Older adults are particularly vulnerable to severe complications, hospitalisations and death from the disease.
Several flu vaccines are already available in the United States, including three specifically recommended for people aged 65 years and older. However, experts say mRNA technology offers an important advantage because vaccines can be manufactured more rapidly than traditional influenza vaccines, potentially allowing for quicker responses when circulating strains change unexpectedly.
"Having this technology available puts us in a better position to be prepared for emerging strains in the future," said Dr. Flor Munoz-Rivas of Texas Children's Hospital, who serves on the FDA's advisory panel.
Clinical trial findings presented to the committee included a study involving approximately 40,000 adults aged 50 years and older. The results showed that Moderna's mRNA flu vaccine reduced influenza cases by about 27 per cent compared with another routinely used influenza vaccine.
In a separate study involving adults aged 65 years and older, the vaccine generated strong immune responses when compared with a high-dose influenza vaccine already recommended for senior populations.
FDA adviser Dr. Anna Durbin of Johns Hopkins University described the immune response data as "very compelling" and said the vaccine appears highly promising.
Moderna officials told the advisory panel that the company's ability to rapidly manufacture vaccines tailored to currently circulating influenza strains could potentially prevent thousands of hospitalisations among older adults.
The company noted that influenza strains used for seasonal vaccine production are selected several months before the start of each flu season. Because influenza viruses continuously mutate, vaccine formulations do not always perfectly match circulating strains by the time flu season arrives.
FDA reviewer Dr. Timothy Brennan indicated during the meeting that the agency may be open to approving the vaccine ahead of the upcoming influenza season despite the need for additional information regarding its use in frail older adults and individuals with weakened immune systems.
If approved, Moderna plans to conduct a large post-approval study involving approximately 400,000 adults aged 65 years and older. Half of the participants will receive the mRNA vaccine, while the remainder will receive one of the currently available senior-specific influenza vaccines. The study is expected to continue for two influenza seasons.
Clinical trial data showed no major safety concerns associated with the vaccine. However, recipients experienced temporary side effects including injection-site pain, fever, headache, fatigue and muscle aches.
The FDA noted that such reactions are common with mRNA vaccines and generally indicate that the immune system is responding appropriately.
"Your immune system is responding," said Dr. Hayley Gans, a Stanford Medicine paediatrician and FDA adviser, emphasising the importance of explaining these temporary reactions to vaccine recipients.
The vaccine's journey to potential approval has not been without controversy. Earlier this year, Moderna's application became the centre of a public dispute when then-FDA vaccine chief Dr. Vinay Prasad questioned the company's clinical trial design and requested additional comparisons with high-dose influenza vaccines used in older adults.
Moderna challenged the concerns, noting that FDA staff had previously approved the main study design and submitted additional data from a separate study involving senior populations. The FDA subsequently accepted the company's application.
Beyond older adults, Moderna is also studying the mRNA influenza vaccine in younger adults and plans to begin a separate study involving adolescents aged 9 to 17 years later this year.
If approved, mFluSVA would become the world's first mRNA-based influenza vaccine, potentially marking a new chapter in vaccine development and strengthening preparedness against future seasonal influenza outbreaks and emerging strains.
Stay informed, stay alert!
CLICK HERE TO JOIN Medical News Pakistan on WhatsApp for real-time health alerts, expert insights, and breakthrough medical discoveries.