The Essential Role of Sleep in Immunity

Want to ensure your vaccination offers the greatest protection against COVID-19? Sleep—and sleep well—before and after your vaccine appointment, because natural sleep boosts the immune system significantly.

The authors of a January 2021 article in Sleep Diagnosis and Therapy are even more specific. They suggest at least two nights of full sleep before receiving the COVID vaccine, followed by several more nights of sufficient sleep to minimize, or avoid, any side effects of the vaccination. Their comments follow the publication of a study in a 2020 issue of theInternational Journal of Behavioral Medicine, in which scientists report an association between sleep duration and the effectiveness of influenza vaccine.  Sleep, the study authors say, seems to increase the body’s “immunological memory,” meaning the immune system is more likely to recognize—“remember”—invading viruses and other pathogens and develop a quicker and more potent antibody response against them once a vaccine is injected.

Sleep and “Immunological Memory”

The link between sleep and the immune system is central to a study appearing in a 2019 edition of the Journal of Experimental Medicine. In the article, researchers describe a “potential mechanism” by which sleep advances the response of the body’s T-cells, lymphocytes that can differentiate between “good” and “bad” cells and kill those that are cancerous or infected with viruses like COVID. Other studies have shown that the quantity of T-cells in the bloodstream decreases in people who are sleep-deprived—getting less than five or six hours of sleep a night—and that insufficient sleep cripples T-cells’ ability to recognize and fight incoming pathogens.

Such findings should not be surprising. In fact, nearly 20 years ago, scientists from the University of Chicago and Ohio State University, writing in the Journal of the American Medical Association, were already warning that “response to influenza vaccination may be impaired in individuals with chronic partial sleep restriction.” They advised that their study results “support the concept that adequate amounts of sleep are needed for optimal resistance to infectious challenge.”

But COVID Vaccines Are 95 Percent Effective, Right?

News sources are reporting that the various COVID vaccines currently in circulation are as much as 90 percent or 95 percent effective. But these numbers are based on controlled clinical trials. The precise extent of the vaccines’ infection-fighting capabilities over time among the general public is not yet fully known. Many variables—one of them being sleep—modulate the effects of a vaccine in any given individual.   

Ohio State University scientists undertook a review of nearly 50 vaccine studies, some published as far back as 30 years. They found evidence that unhealthy lifestyle habits, lack of exercise, anxiety, stress, mental health disorders like depression, and, yes, sleep deprivation could significantly decrease the benefits of vaccination. Negative health factors prevented sufficient antibody production, reduced the time period of immunity protection, or enhanced or prolonged the vaccine’s unwanted side effects, they concluded. Their report is published in the January 2021 Perspectives on Psychological Science.