Lack of sleep would decrease the effectiveness of vaccines

The quality and duration of sleep are essential to preserve our overall health. Now, scientists associate the amount of sleep around vaccination with the immune response to it. The result would only be significant in men.

The immune protection offered by a vaccine depends largely on an individual response to it. To visualize this protection, scientists use the antibody response as a biomarker in the body. However, recent studies have shown a great variability in the antibody response to the same vaccine against Covid-19 in healthy adults who have never been infected with the virus. Certain risk factors seem to play a role in this variability, such as sex, age, adiposity, smoking history and hypertension. In general, men are less protected than women, and people who suffer from obesity are less protected than those who do not suffer from it. ” None of these risk factors, however, can be targeted by prompt behavioral interventions aimed at optimizing the humoral response. write the researchers of a new study published in Current Biology.

Sleep duration is a controllable factor

On the contrary, sleep appears to be a controllable factor. According to the authors, increasing the duration of sleep at the time of vaccination could enhance the antibody response. In order to summarize the evidence linking the total amount of sleep in the days before vaccination to the antibody response in healthy adults, the researchers performed a meta-analysis. They scoured existing studies on the topic, then combined and reanalyzed the results of seven studies looking at vaccination against viral infections.

Several striking associations were found. Compared to a sleep duration considered normal (seven to nine hours), sleep time of less than six hours per night around vaccination reduces the antibody response. This reduction would be similar to the decrease in antibodies from the Covid-19 vaccine over a two-month period. In addition, every hour of sleep counts, bringing efficiency in the production of antibodies.

In women, immunity is more influenced by sex hormones

It should be noted that the researchers found differences in results between people of different genders and ages. People over the age of 65 were less impacted by lack of sleep on the production of antibodies than those aged 18 to 60. Moreover, the general result found was only significant in men, and much more variable in women. ” We know from immunological studies that sex hormones influence the immune system said author Karine Spiegel of the French National Institute of Health and Medicine. ” In women, immunity is influenced by menstrual cycle status, contraceptive use, menopause and post-menopausal status, but unfortunately none of the studies we summarized contained data on levels of sex hormones. »

That’s one of the reasons the authors say there’s still a lot to learn about sleep duration and vaccination. Larger scale studies are needed to define the time window around vaccination where optimizing sleep duration is most beneficial, causes of gender disparity in impact of sleep on response, as well as the amount of sleep needed to protect the response.