A yearly flu vaccine has not been proven to prevent flu-related deaths in people over the age of 65, according to a review in the Lancet medical journal.
Nonetheless, the U.S. Centers for Disease Control and Prevention (CDC) recommends the flu shot for this purpose, citing research about the 36,000 yearly deaths and 200,000 annual hospitalizations for flu-related illness in the United States.
No studies have conclusively proven that flu shots prevent flu-related deaths among the elderly, according to the review, and some of the support for this practice is based on flawed data.
While some studies have shown a benefit for flu shots in younger adults, only a small number of trials included people over the age of 70 -- even though about 75 percent of flu-related deaths occur among that age group.
There is also evidence, according to the researchers, that the flu vaccines are less effective in older people because the elderly have lower immune activity.
Flu shots do not always prevent infection with the flu, though they can make the illness less serious.
The Lancet Infectious Diseases October 2007, Volume 7, Issue 10, Pages 658-666
Medical News Today September 25, 2007
Reuters September 24, 2007