Sleep better and flu shots will be more effective, says study

September 25, 2002

BY JIM RITTER HEALTH REPORTER

Flu shots might not work very well if you don't get enough sleep, a finding, University of Chicago researchers said Tuesday, that lends support to the common belief that a lack of sleep makes you more prone to flu, colds and other ailments.

The researchers gave flu shots to 11 healthy young men who had been sleeping just four hours a night for four straight nights. They compared them with 14 other young men who slept normally before getting a flu shot and found that, 10 days after being vaccinated, the sleep-deprived group produced fewer than half as many flu-fighting antibodies. By three to four weeks after vaccination, though, there were no significant differences between the two groups.

"These results suggest that the response to influenza vaccination may be impaired in individuals with chronic partial sleep restriction," researchers Karine Spiegel and Eve Van Cauter of the U. of C. and John Sheridan of Ohio State University wrote in a "research letter" that appears in today's Journal of the American Medical Association.

Earlier studies have found that elderly people don't respond as well to flu shots as the young. The reason might be that old people generally don't sleep as well, Van Cauter said.

Sleep deprivation appears to be a growing problem, especially among shift and night workers. A National Sleep Foundation Poll this year found that 15 percent of adults reported sleeping fewer than six hours a night on week nights, up from 12 percent in 1998. Adults now sleep an average of 6.9 hours a night, down from nearly nine hours in 1960.

The new study--funded by the Mind-Body Network of the MacArthur Foundation and by the National Institutes of Health--adds to a growing body of research on how sleep affects the immune system. Earlier studies found that volunteers who went one, two or three nights without sleep showed reduced immune-system function. And the reason flu patients get so sleepy might be related to the immune system working in overdrive, Van Cauter said.

For those at greatest risk for serious flu complications--and that includes children 6 months to 23 months old, the elderly, people with chronic health conditions and women more than three months pregnant during flu season--October and November are the best times to get a flu shot, according to the U.S. Centers for Disease Control and Prevention. For others, November is the best time.

Flu season runs November through March. On average, about 114,000 people a year are hospitalized and 20,000 die from flu in the United States. Most are over 65. West Nile virus has killed 98 people so far this year.