Recommendations to vaccinate the elderly against the flu may be based on an overly optimistic view of how well the vaccine works, a study suggests. Out of a large group of seniors who were given flu shots, the biggest reductions in hospitalizations and deaths were before the start of the influenza season, implying that current vaccines offer less protection than believed.
Yet researchers do not call on older people to skip annual flu shots. Instead, they urge increased vigilance to keep the potentially deadly virus in check, such as by vaccinating children first.
"The elderly should continue to get vaccinated," said Dr. Lisa Jackson of the Group Health Cooperative in Seattle, Washington, who led the study. "But if you can prevent others from ever coming into contact with the flu, that is a better way to stop it."
Children tend to get the flu earlier than everyone else because school settings act as natural incubators for spreading germs. In fact the Centers for Disease Control and Prevention recommends vaccinating both children between 6 months and 5 years-old and adults 65 and older.
The problem, Jackson said, is that no one really knows just how much protection the vaccine provides to those who are older and more likely to be sick. "We cannot exclude that there is an effect," she said. "What this means is that we don't have all the information we want."
As part of the study, which was published in the International Journal of Epidemiology, Jackson's team reviewed eight years of medical records from nearly 74,000 members of a local health maintenance organization (HMO). The members were at least 65 years of age. Jackson examined the rate of death and hospitalizations over a full 12-month period.
In every year studied, the risk of death from any cause was lowest before the flu season and then increased progressively through the winter months and later that summer. Compared to those who were not vaccinated, seniors who received the vaccine had a lower rate of death and hospitalizations from pneumonia-like complications before the flu season. The decrease in death rate prior to flu-season makes it difficult for researchers to associate the benefits of the vaccine
Health
As part of a separate study published in the same journal, Jackson found that older people who had medical conditions that made it difficult to get around were less likely to get flu shots. What this may suggest, Jackson said, is that the perceived benefits from the vaccine may not apply to those who are already unhealthy.
"There is a large group of terminally ill patients who are going to die," she said. "We can't tell how effective the vaccine is."
In an accompanying editorial, Drs. Paul Glezen and Lone Simonsen contend that better vaccines are clearly needed. Until then, other strategies should be considered to help further protect the old and sick. "Immunization of school children," they write, "will reduce exposure of vulnerable patients."
Jackson said that inoculating kids may not be as easy as having seniors line up for shots. But the benefits are increasingly apparent.
"This is starting to fit together," Jackson said. "If you can prevent the flu in one high risk group, you can stop it from spreading outwards.
