Study: Flu shot does not reduce risk of death

Canadian researchers are challenging the widely held belief that flu shots help protect older people from potentially deadly diseases such as pneumonia.

While the researchers say the vaccine does protect against certain strains of influenza, its overall benefit seems to have been exaggerated by so-called observational studies that found a big reduction in “all-cause mortality” among older patients who’d gotten a flu shot.

After compensating for a variety of factors that the researchers said weren’t considered or available in the earlier studies, the study authors concluded that any “all-cause mortality” benefit “if present at all, was very small and statistically non-significant and may simply be a healthy-user artifact that they were unable to identify.”

The new research was expected to be published in the first September issue of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.