Health
Universal Flu Vaccine Clears Phase 3 Trials
A universal flu vaccine has cleared Phase 3 clinical trials with 85 percent efficacy across all major influenza strains. If approved, it could replace the annual flu shot guessing game with a vaccine that lasts for years.
Illustration: Clear News
A universal flu vaccine has cleared Phase 3 clinical trials, showing 85 percent efficacy against all major influenza strains, the manufacturer announced Tuesday. The result could end the annual cycle of reformulating flu shots to match predicted strains.
The trial enrolled more than 20,000 participants across four continents over two flu seasons. Unlike conventional flu vaccines, which target the virus's rapidly mutating surface proteins, the new vaccine targets conserved regions of the virus that change little from year to year.
That design choice paid off. Participants were protected against H1N1, H3N2, and both lineages of influenza B, including strains that did not match the season's predictions. Conventional vaccines, by contrast, average 40 to 60 percent efficacy and sometimes fall below 30 percent in mismatched years.
"This is the result the field has been working toward for two decades," said an independent vaccine researcher not involved in the trial. "A vaccine that does not need to guess which strain is coming next changes everything."
From annual shot to lasting protection
The company reports that protection lasted through both trial seasons without a booster, suggesting the vaccine could be given every two to three years instead of annually. Researchers are studying whether a longer interval is possible.
The vaccine uses an mRNA platform, similar to the technology behind several COVID-19 vaccines, but with a novel design that presents the conserved viral regions to the immune system. Side effects were consistent with other mRNA vaccines: sore arms, fatigue, and mild fever lasting a day or two.
Regulatory path and availability
The manufacturer plans to submit the vaccine for regulatory review in the United States and Europe by the end of the year. If approved on a standard timeline, it could be available for the 2027-2028 flu season.
Public health experts caution that manufacturing scale will matter as much as science. Global flu vaccine production currently covers less than a third of the world's population each year. The company says it has secured production capacity for 200 million doses in the first year.
Influenza kills an estimated 290,000 to 650,000 people worldwide each year. A vaccine with 85 percent efficacy and multi-year protection could prevent a large share of that burden, particularly in low-income countries where annual vaccination campaigns are hardest to run.