Sunday, April 20, 2014

’Flu shot did little to protect elderly

TORONTO—This year’s ’flu vaccine provided little protection to people 65 and older who got a shot, new data released by the U.S. Centers for Disease Control revealed.
When it came to the influenza A strain H3N2, the main virus circulating in North America this winter, the study found the vaccine cut an older adult’s risk of getting sick enough to need to see a doctor by a mere nine percent.

“Clearly it’s much lower than we had hoped for,” Dr. Joe Bresee, a ’flu expert with the CDC, said in an interview.
When all three strains in the vaccine were taken together, the study suggested the shot was about 27 percent effective in preventing seniors from becoming ill enough to need to see a doctor.
For all age groups taken together, the effectiveness estimate was 56 percent.
Bresee said seniors need to know that even if they got a ’flu shot this year, they still could get sick and should see a doctor about taking antiviral drugs if they do.
H3N2 viruses hit the elderly hard and there has been a big spike in hospitalizations among that demographic this winter.
“We wanted to make sure that people knew that—especially if you’re elderly to know that—because we still want to communicate the fact that if you do get sick, get antivirals,” Bresee stressed.
“And don’t assume just because you got the vaccine that that ’flu-like illness you’ve got can’t be ’flu,” he added.
While the results are disturbing, they aren’t entirely surprising.
In recent years, a number of studies have shown that ’flu vaccine doesn’t work as well as had been previously believed, and provides particularly poor protection in older adults, who are among those hardest hit by ’flu.
“Clearly the influenza vaccine world is in a state of rather significant transition—one from where we overstated the effectiveness of the vaccine and now one where we’re confronted head-on with the scientific data which says that the impact is at best moderate for most age groups, and in some age groups significantly below that which had been previously stated,” said Dr. Michael Osterholm, director of the Center for Infectious Diseases Research and Policy at the University of Minnesota.
In the past year or so, Osterholm and colleagues have published a scientific analysis and a major report on ’flu vaccine, concluding that new and better ’flu vaccines are needed because the existing products aren’t getting the job done.
This latest CDC report, for instance, showed that young adults—those aged 17-49—who got the ’flu vaccine this year saw their risk of H3N2 infection cut by only 46 percent.
This is in the age group in which vaccines typically work well and in a year in which the H3N2 virus in the shot is closely matched to the ones making people sick.
“I believe that 46 percent protection is better than zero,” Osterholm conceded.
“But it is far short of what we want and what we ultimately believe we can have with better vaccines,” he added.
It is important to note the study measured the ability of the vaccine to protect against what the ’flu research world calls “medically-attended ’flu.”
This type of study actually may overestimate the effectiveness of the vaccine, some experts say.
For one thing, it doesn’t capture a picture of the percentage of people who got a shot and got the ’flu, but did not go to a doctor.

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