Flu Shots Don't Reduce Senior Deaths

[robin]

Flu shots don't reduce senior deaths

Vaccinations have risen dramatically since 1968, but death rates are stable,
experts say.

By Robyn Shelton
Sentinel Medical Writer
ORLANDO SENTINEL
February 15, 2005

There is no evidence flu vaccines help elderly Americans avoid death from
the disease, according to a study released Monday that tracked flu mortality
rates during a 33-year period.

Public-health officials quickly took issue with the findings and expressed
fear that the elderly might forgo immunizations if they think the shots will
not protect them.

For decades, doctors have been advising people 65 and older to get flu shots
because they are most susceptible to serious or fatal complications from the
disease.

Logically, doctors would expect flu deaths to drop as more of the elderly
are vaccinated annually. But researchers found the influenza death rate
fairly stable between 1968 and 2001, even though the percentage of seniors
getting shots increased from 15 percent in the 1970s to 65 percent in 2001.

If the vaccines aren't making a dent in mortality, a natural question is:
Why bother?

But even the study's lead author said Monday that older people still need to
be vaccinated every year. What's important is that they be given more
effective vaccines, said Lone Simonsen, a senior epidemiologist at the
National Institute of Allergy and Infectious Diseases, a branch of the
National Institutes of Health.

"We're not saying we should not immunize the elderly," said Simonsen. "But
what we are saying is, clearly, there's room for improvement.

"Some elderly fail to respond to the vaccines, and there's room to improve
how we protect them."

The study was published in the medical journal Archives of Internal
Medicine. Public-health officials, who strongly recommend vaccination for
everyone age 65 and older, criticized the study's methodology.

They said researchers did not separate vaccinated seniors from those who did
not get shots -- nor did they weed out people with high-risk conditions such
as asthma or diabetes, said William Thompson, an epidemiologist with the
National Immunization Program at the Centers for Disease Control and
Prevention.

Also, the study did not account for the fact that flu season has become
longer over the years, giving people more time to pick up the virus. These
factors could have skewed the researchers' findings, he said.

Thompson said he completely rejects the study's conclusions.

"The big point we want to get across is that we still consider persons 65
and older as the highest-risk group with respect to influenza deaths, and
this particular study wouldn't alter any vaccine recommendations," he said.

But Simonsen defended her methodology and said she used an approach widely
accepted by epidemiologists, the experts who study diseases.

For the research, Simonsen and her colleagues used a common statistical
model to estimate how many of the elderly people who died every winter since
1968 likely succumbed to the flu.

She said health officials have used the same kind of model for 40 years. Flu
deaths can't be counted directly -- for example, by examining death
certificates -- because influenza often is missed as the underlying cause.

Simonsen said many influenza deaths occur when the flu leads to pneumonia.
But by the time the lung disease takes hold, the influenza virus usually has
cleared the person's system.

"This is not an easy disease to track," she said.

The researchers then compared the influenza mortality rate for any given
year with the percentage of seniors vaccinated that flu season. Simonsen
said they found the mortality rate was relatively "flat," never accounting
for more than 10 percent of deaths in any winter. The rate was stable
despite the increasing percentage of the elderly who got shots.

She said earlier studies suggested flu shots cut a person's chance of dying
by as much 50 percent. Her data found no basis for that assumption.

"We're not saying the vaccine is inherently bad," she said, "but it's
certainly not as good as we thought it could be."

Physicians have long known that effectiveness of flu vaccines wanes as
people get older because their immune systems don't work as well as younger
people's, said Dr. Frederick Southwick, a professor and chief of infectious
diseases at the University of Florida in Gainesville.

But flu vaccines still help people avoid serious illness, and doctors need
to make sure their older patients have the option of getting a shot, he
said.

"You don't want to walk away from this thinking you shouldn't vaccinate the
elderly," Southwick said. "There is plenty of evidence that the vaccine is
safe and you can benefit from it. . . . What this [study] tells me is that
the vaccine companies need to develop a more powerful vaccine so that more
elderly will respond to it."

Despite the debate over Simonsen's numbers, no one disagrees with her
opinion that improved vaccines would protect more people by better
stimulating their immune systems so they can fight off dangerous viruses.

A spokeswoman for the Florida Department of Health said people also need to
keep in mind that "herd immunity" is another benefit of vaccinating. To put
it simply, the more people get vaccinated, the less chance the virus has of
spreading. Lindsay Hodges said flu season has started to pick up in Florida
in recent days, and officials still are urging people to get shots.

"The important thing to remember about the flu vaccine is that it helps
prevent the serious complications that lead to hospitalization" such as
pneumonia, she said.

Robyn Shelton can be reached at rshelton@orlandosentinel.com or
407-420-5487.