firefighterjake said:
However, influenza can be a fatal illness for some folks -- especially seniors or folks who are at risk. In the U.S. it's in the top 10 causes of death.
http://www.cdc.gov/nchs/fastats/deaths.htm
From the article
Nonetheless, in 2004, Jackson and three colleagues set out to determine whether the mortality difference between the vaccinated and the unvaccinated might be caused by a phenomenon known as the “healthy user effect.†They hypothesized that on average, people who get vaccinated are simply healthier than those who don’t, and thus less liable to die over the short term. People who don’t get vaccinated may be bedridden or otherwise too sick to go get a shot. They may also be more likely to succumb to flu or any other illness, because they are generally older and sicker. To test their thesis, Jackson and her colleagues combed through eight years of medical data on more than 72,000 people 65 and older. They looked at who got flu shots and who didn’t. Then they examined which group’s members were more likely to die of any cause when it was not flu season.
Jackson’s findings showed that outside of flu season, the baseline risk of death among people who did not get vaccinated was approximately 60 percent higher than among those who did, lending support to the hypothesis that on average, healthy people chose to get the vaccine, while the “frail elderly†didn’t or couldn’t. In fact, the healthy-user effect explained the entire benefit that other researchers were attributing to flu vaccine, suggesting that the vaccine itself might not reduce mortality at all. Jackson’s papers “are beautiful,†says Lone Simonsen, who is a professor of global health at George Washington University, in Washington, D.C., and an internationally recognized expert in influenza and vaccine epidemiology. “They are classic studies in epidemiology, they are so carefully done.â€
In 1989, only 15 percent of people over age 65 in the U.S. and Canada were vaccinated against flu. Today, more than 65 percent are immunized. Yet death rates among the elderly during flu season have increased rather than decreased. There’s some merit to this reasoning. Unfortunately, the very people who most need protection from the flu also have immune systems that are least likely to respond to vaccine. Studies show that young, healthy people mount a glorious immune response to seasonal flu vaccine, and their response reduces their chances of getting the flu and may lessen the severity of symptoms if they do get it. But they aren’t the people who die from seasonal flu. By contrast, the elderly, particularly those over age70, don’t have a good immune response to vaccine—and they’re the ones who account for most flu deaths.
Only four studies were properly designed to pin down the effectiveness of flu vaccine, he says, and two of those showed that it might be effective in certain groups of patients, such as school-age children with no underlying health issues like asthma. The other two showed equivocal results or no benefit.
