Image of Marion Hofmann Bowman, M.D.

People who received a flu vaccination this season were 24% less likely to test positive for COVID-19 or have severe disease than those who didn’t get a flu shot, investigators say.

The findings came from a review of medical charts and data for more than 27,000 patients who were tested for COVID-19. Flu-vaccinated patients who did test positive for COVID also had lower odds of being hospitalized than their non-vaccinated peers. What’s more, those who were hospitalized for the coronavirus were less likely to require mechanical ventilation and had shorter stays, reported lead author Marion Hofmann Bowman, M.D., a cardiologist with the University of Michigan.

With coronavirus vaccines not readily available to everyone, the findings highlight flu vaccination as a preventive measure against COVID-19, Hofmann Bowman said. Although the greatest benefit from influenza vaccines comes from prevention of influenza, especially in the elderly, this additional potential for COVID-19 protection may encourage hesitant patients to get a flu shot, she added.

Even if the direct link between the prevention of COVID-19 and the influenza vaccine is small, an overall reduction in flu and COVID-19 cases in vaccinated people will preserve healthcare resources for those with COVID-19, the authors concluded.

The study was published in the American Journal of Infection Control.