By Deborah Kotz Globe Staff

A wide body of research suggests that those who don’t get enough sleep -- fewer than six or seven hours a night -- are more likely to develop a chronic disease such as diabetes or respiratory infections. Now a new study from the University of Pittsburgh suggests that those who are sleep-deprived also don’t get the full immune response from vaccinations, which could leave them susceptible to diseases that they’re vaccinated against.

The study published this week in the journal Sleep examined the immune responses in 125 adults ages 40 to 60 who received a vaccine against hepatitis B and found that those who slept fewer than six hours a night around the time they received the vaccine had a higher risk -- 11.5 times higher -- of remaining unprotected from the virus six months later than those who slept seven or more hours a night.

Nearly 15 percent of the study participants failed to obtain protection from the vaccine six months after they received all three injections in the series.

While given to infants, a hepatitis B immunization is also recommended for certain adults who are at high risk of contracting the sexually transmitted disease because they aren’t in a monogamous relationship, for example, or are having sex with a hepatitis B carrier, according to the US Centers for Disease Control and Prevention.

“These findings provide initial evidence that natural variation in sleep may contribute to clinically relevant differences in the magnitude of immune responses to vaccination,” write the study authors, “possibly providing a physiologic basis for observed differences in susceptibility to infection.”