Vaccines may not work as well without a good night's sleep, says a new study.

Researchers found that adults who slept less than six hours a night were less protected from hepatitis B even after a shot.

The study authors looked at 125 men and women who took the double dose vaccine, said WebMD.

The study found that people who did not get enough sleep were 11.5 times more likely to be unprotected by a vaccine than those who slept more than six hours.

“This study shows clear evidence of a link between amount of sleep and an immune process relevant to infectious disease risk,” said lead author Aric Prather, of the the University of San Francisco and UC Berkeley, reported Time.

The reason behind the lack of protection is likely due to sleep's role in hormone production, which keeps people healthy and their immune system functioning.

Time reported that hormone disruptions caused by a lack of sleep can pose various health risks like cancer.

Researchers said that the findings may help doctors better protect their patients from the risks associated with a lack of sleep, particularly those who have just received vaccines.

"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," said Prather, according to MSNBC.

The study was published in the journal Sleep.

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