CHICAGO -- Despite the advent of a vaccine four decades ago, flu-related deaths in the United States have risen dramatically since the 1970s, and influenza now claims more lives each year than AIDS, researchers say.
The rising death toll is attributed largely to the nation's growing number of elderly people, who are especially vulnerable to the flu.
Only about 65 percent of older people get vaccinated, and the annual shots do not protect aging immune systems as well as they do younger ones.
The U.S. death toll surged fourfold from 16,263 in 1976-77 to 64,684 in 1998-99, the Centers for Disease Control and Prevention reported. Flu deaths now average about 36,000 a year, up from 20,000 in previous estimates, the CDC said.