Lack of Sleep

You've probably noticed you're more likely to catch a cold if you pull a lot of all-nighters. But lack of sleep can also compromise your immune system's response to vaccines. And in some cases, make the shots useless. So says a study in the journal Sleep. Researchers gave 125 healthy, middle-aged men and women the Hepatitis B vaccine a three-part vaccine given at one, two and six months. And during that time, volunteers tracked their sleep habits. Six months after the final booster, researchers took blood samples to see if the patients had rallied sufficient numbers of antibodies against Hep-B. Eighteen patients had not the vaccine had failed. Turns out the vaccine was almost 12 times as likely to fail in volunteers who regularly slept fewer than six hours a night compared to those who snoozed more than seven. Makes sense, because previous studies have shown that sleep deprivation cuts numbers of B and T cells which coordinate the immune system's attack on bad guys. So remember, vaccines aren't magic. You still need a good night's sleep to give'em a fair shot.