A new study led by researchers at Washington University School of Medicine in St. Louis found that an “investigational mRNA influenza vaccine helps the immune system recognize a wider range of influenza viruses than today’s standard flu shot, offering stronger and potentially longer-lasting protection.”

The vaccine is currently under review by the FDA and has been the subject of some flip flopping from federal regulatory agencies, as HPN has reported.

Influenza viruses “change as they spread from person to person, picking up small genetic mutations over time.” Immune protection from past infections or vaccinations wanes over time, so a vaccine that “elicits broader antibodies could help limit this viral escape by making it harder for the virus to evade immunity with just a few mutations.” Strain mismatch with today’s vaccines can reduce the efficacy of flu vaccines from around 60% down all the way to 19%.

In a phase 3 clinical trial, Moderna found that its “mRNA-based flu vaccine reduced the risk of illness by 26.6% more than the standard flu vaccine in older adults.” The researchers involved with the WashU study found a “stronger immune response in participants who received the mRNA vaccine compared with participants who received the standard flu shot.”