How Your Sleep Habits Predict Your Vaccine Response

Rather than manipulating sleep in a lab, this study simply measured how 125 midlife adults, aged 40 to 60, actually slept in their own homes using wrist actigraphy, then tracked their antibody response across the standard three-dose hepatitis B vaccination series. People who slept fewer hours on average produced a measurably weaker antibody response after the second and third doses, and shorter sleep also predicted a lower likelihood of achieving full clinical protection six months after the final dose. The effect held after accounting for age, sex, body mass index and how strongly someone had responded to the very first dose.

This is an observational study, so it shows a link rather than definitive proof that improving sleep would improve any individual's vaccine response, and sleep efficiency and self-reported sleep quality weren't significant predictors, only actual sleep duration was. The researchers themselves were careful to call this preliminary evidence rather than a reason to delay a vaccine appointment over one rough night. What it does add is a real-world demonstration, in adults in their 40s and 50s specifically, that habitual sleep duration over time may be one of the behavioural factors shaping how well a vaccine actually works.