Bombshell Study: Flu Shot Linked to Higher Risk of Infection in 2024–2025 Season
Originally published: 2025-04-13
In a stunning revelation that’s sending shockwaves through the medical and public health communities, new research out of the Cleveland Clinic has found that the 2024–2025 seasonal influenza vaccine not only failed to protect healthcare workers—but was associated with a higher risk of infection.
The study, conducted among 53,402 working-age employees, shows that those who received the flu shot were 27% more likely to contract the flu than those who didn’t. That translates to a negative vaccine effectiveness of -26.9%, a figure that directly contradicts decades of public messaging promoting the annual flu shot as an essential tool to prevent illness, protect patients, and reduce hospital burden.
“This isn’t just a blip,” said one medical professional familiar with the data. “This calls into question the very foundation of our influenza vaccination campaigns.”
The study, published on April 4, 2025, on the preprint server medRxiv, used rigorous Cox proportional hazards modeling and treated vaccination as a time-dependent covariate—an advanced methodology that sidesteps the biases found in traditional “test-negative” vaccine studies. Unlike previous research that relied on odds ratios and often overstated effectiveness, this study directly calculated risk, providing one of the clearest pictures yet of vaccine performance.
And the picture is grim.
The vaccinated group experienced a sharper rise in infections as the season progressed. Though more vaccinated individuals were tested, the rate of positive flu cases among those tested was not inflated by increased testing behavior—indicating that the rise in infections was real.
The implications are staggering. For years, Americans have been told—by the CDC, hospitals, and the media—that the flu shot is a safe, effective, and necessary protection against seasonal illness. Healthcare workers in many institutions are required to get vaccinated as a condition of employment.
Now, this landmark study suggests not only that the vaccine was ineffective this season—but that it may have backfired.
Where is the accountability? Where is the outrage?
With no external funding and no conflicts of interest reported, the Cleveland Clinic team’s findings should raise red flags for every policymaker, health system, and individual being told to roll up their sleeve each fall.
If this is the best science can do after decades of promises, hundreds of millions in funding, and countless campaigns pushing flu shots as “our best defense”—it’s time for a reckoning.
The public deserves answers. They also deserve truth—something this study finally delivers.
CLICK HERE to review the study
