Flu shots for elderly questioned

The influenza vaccine, which has been strongly recommended for people over 65 for more than four decades, is losing its reputation as an effective way to ward off the virus in the elderly.

A growing number of immunologists and epidemiologists say the vaccine probably does not work very well for people over 70, the group that accounts for three-fourths of all flu deaths.

The latest blow was a study in The Lancet in August that called into question much of the statistical evidence for the vaccine's effectiveness.

The authors said previous studies had measured the wrong thing: not any actual protection against the flu virus but a fundamental difference between the kinds of people who get vaccines and those who do not.

This contention is far from universally accepted. And even skeptics say that until more effective measures are found, older people should continue to be vaccinated, because some protection against the flu is better than none.

Still, the Lancet article has reignited a longstanding debate over claims that the vaccine prevents thousands of hospitalizations and deaths in older people.

"The whole notion of who needs the vaccine and why is changing before our eyes," said Peter Doshi, a doctoral candidate at MIT who published a paper on the historical impact of influenza in May in The American Journal of Public Health.

The Lancet paper, by Michael L. Jackson and colleagues at the Group Health Center for Health Studies in Seattle, was based on an analysis of medical charts of thousands of elderly members of an HMO.

The study found that people who were healthy and conscientious about staying well were the most likely to get an annual flu shot. Those who are frail may have trouble bathing or dressing on their own and are less likely to get to their doctor's office or a clinic to receive the vaccine. They are also more likely to be closer to death.

Dr. David K. Shay of the Centers for Disease Control and Prevention, a co-author of a commentary that accompanied Jackson's study, agreed that these measures of health and frailty "were not incorporated into early estimations of the vaccine's effectiveness" and could well have skewed the findings.