A study published in Current Biology in March 2023 suggests that getting sufficient sleep in the days surrounding vaccination is key to optimising antibody responses. Although this might seem an obvious assumption, the authors state that “simple behavioural interventions” associated with vaccine responses are “yet to be identified”. Thus, their meta-analyses summarised evidence that links amount of sleep with antibody response in healthy adults.  

Vaccination during COVID-19 

The authors indicate that in response to the pandemic, vaccination was “widely expected to be effective in controlling” the disease. However, “only 63% of adults worldwide” have been “fully vaccinated”, a term that is contested in the light of emerging variants and subsequent boosters.  

“Thus, the vaccination effort needs to continue.” 

Alongside COVID-19 vaccination efforts, “new” threats like mpox and evolving flu strains are “continuously identified”. This makes vaccination a “major tool for public health in an increasingly globalised society”.  

Context to the study 

The authors note that the protection provided by a given vaccine “depends on the magnitude of the individual immune response”. This can be identified by antibody response, a “clinically significant biomarker of protection”.  

Other studies have identified a “wide variability” in antibody response to the same vaccine in healthy adults. Some of the relevant predictors of “lower antibody titers” include older age, history of smoking, and male sex. However, none of these factors can be targeted by “rapid behavioural interventions” to “optimise the humoral response”.  

A previous study from 2022 demonstrated that immunoglobulin (IgG) antibody titers were affected by “sleep restriction” during an experimental study using an influenza vaccination. Further studies involving influenza and hepatitis vaccines have been carried out with “mixed” results. 

The study 

This study summarised existing evidence using a meta-analytical approach.  

“Our objective is to better inform the scientific community and the public about a relatively easily modifiable behaviour that may optimise vaccine response in the context of the current COVID-19 pandemic.”  

The results obtained indicate that “insufficient sleep duration substantially decreases the response to anti-viral vaccination”. Furthermore, they suggest that achieving “adequate” sleep during the days surrounding vaccination may “enhance and prolong the humoral response”. Although further studies are required, the authors believe that their work shows the importance of sleep to vaccine-induced responses, and they call for additional research into the “window of time around inoculation”, the causes of an observed “sex disparity”, and the amount of sleep required. 

How much sleep do I need? 

The question that many of us might be asking now, then, is how much sleep should I be getting in order to encourage effective vaccine responses in my body? The study describes “short sleep duration” as less than 6 hours a night in adults between 18 and 60, so presumably anything above 6 hours is a strong start! 

However, the authors also acknowledge that “sex impacts the response” to vaccination. Thus, they calculated separate overall effect sizes (ESs) for men and women. When assessed “objectively”, the pooled ES was “large and highly significant for men”, whereas it was “smaller and not significant for women”. This is attributed to “wide variations in sex hormone levels”. This can be due to menstrual cycle, hormonal contraception, menopausal status, or hormonal replacement.  

The authors recommend further investigation, as is so often the case, to determine the impact of sex hormones in the relationship between sleep and antibody response to vaccination in women. An “unprecedented opportunity” for this has been presented in the form of the vaccination programmes to combat COVID-19.  

How much sleep do you get a night, and will this study encourage you to try and improve your sleeping schedule around vaccinations? We look forward to hearing more about the different factors that influence vaccination responses at the World Vaccine Congress in Washington this April.