July 20, 2025
In a groundbreaking step toward ending the seasonal flu cycle, scientists at MIT and Moderna have developed an experimental mRNA-based universal influenza vaccine that targets multiple strains simultaneously — showing over 88% effectiveness in early human trials.
The new vaccine works by encoding multiple conserved viral proteins from different influenza subtypes. Unlike traditional flu shots, which are tailored to match specific circulating strains each year, this next-generation mRNA formulation teaches the immune system to recognize stable, shared viral regions — parts of the flu virus that mutate less often.
“Our goal is to create a vaccine that doesn’t just chase the flu — it stays ahead of it,” said Dr. Lena McCarthy, senior immunologist at MIT’s Koch Institute.
Phase I trials enrolled over 400 participants and demonstrated not only strong antibody responses to H1N1 and H3N2 subtypes, but also broad T-cell activation, which may protect against future, unpredicted variants.
Public health experts have long sought a universal flu vaccine due to the limitations of the current model, which relies heavily on forecasting the next dominant strain and has effectiveness rates ranging from 30% to 60%. The flexibility of mRNA technology — already validated during the COVID-19 pandemic — makes it a powerful platform for tackling flu’s diversity.
“A single annual shot that covers most flu threats could change the way we prepare for flu seasons — and pandemics,” said Dr. Angela Tao, a vaccine strategist at Moderna.
The vaccine is currently moving into Phase II trials later this year, with researchers optimistic it could reach emergency use or limited approval by 2027. If successful, it may not only reduce global flu deaths but also ease the burden on healthcare systems and help prevent flu-related complications like pneumonia and cardiovascular stress.
The findings have been published in Nature Medicine, with peer review ongoing.
