GW Brief: Flu shot may not benefit elderly recipients

Contrary to popular scientific convention, elderly people may not benefit from being vaccinated against the flu, according to research by GW professor Lone Simonsen.

As director of research at the University’s Center for Global Health, Simonsen led a team of researchers who analyzed data from clinical trials of the flu vaccine. Simonsen and her team concluded the effects of the vaccine on the United States’s elderly population, especially those 70, have been exaggerated.

“The implication of the research is not that people should stop getting the flu vaccine,” Simonsen said. “This doesn’t call for any change right now except for researchers to work on more effective vaccines for seniors.”

Winter influenza epidemics in the U.S. cause 36,000 flu-related deaths every year, and about 90 percent of these deaths occur in people age 65 or older. In the past 20 years, Simonsen said there has been a 50 percent increase in the number of elderly people getting vaccinated, but that there has been no significant drop in mortality rates.

“The evidence base for mortality benefits of influenza vaccination in older elderly people is slim and not particularly encouraging with regard to the degree to which influenza vaccination protects elderly people against severe influenza outcomes,” Simonsen wrote in an article summarizing her research findings that was published in the October issue of The Lacent Infectious Diseases journal.

The benefits a flu vaccine may offer elderly people are difficult to quantify in observational trials. Because of the ethics surrounding randomized trials for the elderly that might end in mortality, researchers usually do not study the cohort of people older than 70.

Simonsen said an effective strategy of decreasing the risk of influenza among the elderly could be by immunizing the people who spend time with them. She added that scientists need to expand the way they are thinking in order to provide better healthcare for the elderly.

“It will lead us to do more for them once we realize what is not working,” Simonsen said, “and start looking for new alternatives.”

Another article, titled “Effectiveness of Influenza Vaccine in the Community-Dwelling Elderly,” which was recently published in the New England Journal of Medicine is just one of the many papers that oppose Simonsen’s research.

This research group, led by Kristin Nichol, concluded that even accounting for all the statistical biases, the vaccine was still a significantly effective means of preventing deaths from influenza and linked diseases.

“Influenza vaccination of community-dwelling elderly persons during 10 seasons was associated with substantial reductions in hospitalizations for pneumonia or influenza and in death,” wrote James Nordin, a co-author of the article.

Nordin did not seem fazed when asked his thoughts on Simonsen’s contradictory study.

“It’s fun when you get two studies that come up with two different conclusions,” he said. “It’s great for researchers because they get to do more research.”

Although scientists disagree on the effectiveness of the flu vaccine for the elderly, most emphasize that better research methods are necessary.

“We have a very shaky basis of evidence for the recommendation of vaccinating the elderly as a first priority,” said Jim Sherry, director of the Center for Global Health. “This suggests we need to improve both our monitoring and vaccine development.”

“This research is challenging our comfort level on the efficacy of the current vaccine,” Sherry said, adding that this will stimulate scientists to conduct more research and find a better alternative.

He continued, “This is a good thing, because if we think we have something that works very well, we are less likely to make it better.”

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