Flu shots' protection for elderly questioned

There is no evidence that flu vaccines help elderly Americans avoid death from the disease, according to a study released yesterday that tracked flu mortality rates over 33 years.

Public-health officials quickly took issue with the findings and expressed fear that the elderly may 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 older people 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, the natural question is: Why bother?

But even the study's lead author said yesterday 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," Simonsen said. "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 journal Archives of Internal Medicine.

Public-health officials, who strongly recommend vaccination for everyone age 65 and older, criticized the study's methodology. 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 grown longer over the years, giving people more time to pick up the virus. All these factors may have skewed the researchers' findings, he said.

"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," Thompson said.

The researchers 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 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."

Researchers have long known that people older than 65 do not respond as well to the flu vaccine — or to most other vaccines, for that matter. Their immune systems are simply not as effective at generating antibodies against the virus as those of younger people.

The study should influence the nation's flu-prevention strategy, Simonsen said, perhaps by expanding vaccination to schoolchildren, the biggest spreaders of the virus.

The Centers for Disease Control and Prevention in Atlanta currently recommends flu shots for people age 50 and over, nursing-home residents, children 6 to 23 months old, pregnant women, people with chronic health problems and certain health-care and day-care workers.

It's unlikely that a single study would trigger a change in policy, said CDC spokesman Glen Nowak.

But the former head of the nation's vaccine strategy, Dr. Walter Orenstein, said Simonsen's work "should make us think twice about our current strategy." Orenstein is former director of the CDC's National Immunization Program and now leads a program for vaccine-policy development at Emory University in Atlanta.

A shift to vaccinating schoolchildren, the age group most likely to spread the flu virus, is advocated by colleagues of Orenstein's at Emory in a separate report to be published today in the American Journal of Epidemiology.

Ira Longini, a biostatistics professor at Emory, writes that if 70 percent of schoolchildren were vaccinated, the elderly would be protected without flu shots.

"This would be an effective policy in terms of protecting the elderly because when you vaccinate school-age children, you probably prevent two to three cases of flu among their contacts," Longini said.

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, said Dr. Frederick Southwick, a professor and chief of infectious diseases at the University of Florida.

"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."

The quote from Ira Longini was provided by Newsday.