One might assume that by getting a vaccine against a certain disease -- say, hepatitis B -- you would be protected from it unequivocally. But a new study suggests a factor that could lower the potency of the vaccine -- and it has to do with a nightly activity.
New research, published in the journal SLEEP, shows that regularly getting fewer than six hours of sleep a night is linked with an 11.5-fold increased risk of not actually being protected from a vaccine, compared with those who regularly sleep seven hours a night.
"Based on our findings and existing laboratory evidence, sleep may belong on the list of behavioral risk factors that influence vaccination efficacy," study researcher Aric Prather, Ph.D., who conducted the research while at the University of Pittsburgh but who will soon be an assistant professor at the University of California, San Francisco, said in a statement.
"While there is more work to be done in this area, in time physicians and other health care professionals who administer vaccines may want to consider asking their patients about their sleep patterns, since lack of sleep may significantly affect the potency of the vaccination."
The study included 125 people ages 40 to 60 who were all given the hepatitis B vaccine in three doses: The second dose was given a month after the first dose, and then a booster dose was given at the six month period. The researchers also measured the amount of antibodies they had to hepatitis B after the second and third doses, as well as six months after the final dose.
Throughout this time, the study participants kept sleep diaries, where they tracked when they woke up, when they went to bed and how well they slept. And 88 of the study participants also wore actigraphs as they slept.
While researchers did find a link between the amount of time slept per night and the potency of the hepatitis B vaccine, they didn't find such a link between sleep quality and vaccine potency.
Similarly, recent research showed that being sleep deprived could take the same kind of toll on your immune system as being stressed. Researchers from the Netherlands and the United Kingdom found that white blood cell counts (also known as granulocytes) jumped at night when the men in the study were severely sleep-deprived.