The Food and Drug Administration (FDA) has given the go-ahead to mFlusiva, a new flu vaccine developed by Moderna. This vaccine, designed for adults over 50 years of age, uses mRNA technology, similar to that used in COVID-19 vaccines.
Moderna announced that mFlusiva will begin to be available at select pharmacies ahead of the fall vaccination season, even though there are already several flu vaccine options on the U.S. market.
Vaccines based on mRNA technology were recognized less than three years ago with the Nobel Prize, for their performance against COVID-19, recalls the Associated Press (AP).
"Influenza remains a major public health challenge, and mFLUSIVA offers an important new option for older Americans. This approval also reflects the continued potential of our mRNA platform to help address important public health challenges through continued scientific innovation," Stéphane Bancel, CEO of Moderna, said in a statement.
Efficacy and clinical studies
Data presented by Moderna reveal that mFlusiva showed 27% fewer flu cases in adults aged 50 to 64 compared to traditional vaccines. For the population aged 65 and older, accelerated approval was based on creating a strong immune response.
Although no significant safety concerns were found, mFlusiva may cause temporary reactions such as pain at the injection site, fever and tiredness, reported more frequently than current vaccines.
Let us remember that the approval of mFlusiva was accompanied by controversies, including an initial block by an FDA official. However, following a challenge from Moderna and a unanimous recommendation from an advisory panel, the FDA reconsidered its position.
Differences with other flu medications
mFlusiva is the first messenger RNA (mRNA)-based flu vaccine approved by the FDA, while traditional flu vaccines use older technologies (egg or cell culture). The key differences lie in their technology, production speed, efficacy and side effect profile.
Technology. mFlusiva: messenger RNA encapsulated in lipid nanoparticles. || Traditional: Inactivated virus or viral proteins cultured in chicken eggs or cells.
Content. mFlusiva: Does not contain viruses or viral proteins; just temporary genetic instructions. || Traditional: Contains viral antigens (hemagglutinin) produced in eggs or cell cultures.
Mechanism. mFlusive: The body's cells temporarily produce the virus's hemagglutinin protein to generate an immune response. || Traditional: The immune system directly recognizes the injected viral proteins.
Genetic modification. mFlusive: Does not enter the cell nucleus or modify the DNA; mRNA degrades naturally within hours. || Traditional: There is no genetic material.
Production and adaptation of strains. mFlusiva: Moderna needs only 2–3 months from strain selection to launch, allowing better adaptation to circulating variants and avoiding adaptive mutations. || Traditional: Require 6–8 months of production and are susceptible to adaptive mutations in eggs, which can reduce effectiveness if the selected strain does not match well with the circulating one.
Effectiveness. In clinical trials with more than 40,000 participants, mFlusiva was approximately 27% more effective than the standard flu vaccine in adults aged 50 years and older. || Traditional vaccines have variable effectiveness from year to year depending on the strain match, but they have decades of evidence of safety and reduction in severe disease.
Security. mFlusive: Increased transient reactogenicity (pain at the injection site, fatigue, headache, myalgia, chills), generally mild or moderate and lasting ~2 days. || Traditional: Lower frequency of local and systemic effects; Safety profile well established after decades of use.
Target population. mFlusive: Approved for adults ≥50 years (two groups: 50–65 and ≥65 years), pending further testing in the older age group. || Traditional: Available for all ages (from 6 months), with specific formulations (high dose, adjuvanted) for adults ≥65 years.
