Cambridge researchers report universal mRNA flu vaccine with 95% efficacy in phase 3 trial

Researchers at the University of Cambridge say they have developed a universal mRNA influenza vaccine that performed strongly in a late-stage clinical trial, offering broad protection across major flu strains. The findings, if confirmed, could mark a major step toward simpler and more durable seasonal flu prevention.

According to the study summary, the phase 3 trial enrolled 45,000 participants in 12 countries and found the vaccine was 95% effective against the strains tested. That level of protection would be unusually high for influenza vaccines, which often need to be updated each year to match circulating variants.

The announcement adds to growing interest in mRNA technology beyond COVID-19, as scientists explore whether the platform can speed up vaccine development for other infectious diseases. Experts will now look closely at the full data, including safety results, durability of protection, and how well the vaccine performs in real-world use.

If regulators eventually validate the trial results, the vaccine could reshape seasonal flu prevention and reduce the annual burden of illness, hospitalizations, and missed work or school. For now, the claim remains a significant research milestone awaiting peer-reviewed publication and regulatory review.