For their study, Karine Spiegel at the French National Institute of Health
and Medical Research and Eve Van Cauter at the University of Chicago speculated that
insufficient sleep might damage the ability of the immune system to react to vaccines
and thus result in fewer circulating antibodies.
They pooled the results of seven studies in which a total of 603 participants
between the ages of 18 and 60 had had their antibody response to vaccines monitored
and who had also been asked how many hours of sleep they were getting each night.
Dr Spiegel found that men showed a strong relationship between insufficient sleep
(defined as fewer than six hours of kip a day) and antibody response.
The magnitude of the effect, when sleep duration was recorded objectively by a lab
rather than self-reported by a patient, was similar to the amount of antibody waning
seen in an average person two months after being given the Pfizer-BioNTech covid-19 jab.
The vaccines given to sleep-deprived men, therefore, still provided protection
but the effect was less potent from the start and lasted for less time, on average.
The results were published this week in Current Biology.
Dr Spiegel says that encouraging patients to get plenty of sleep before and after
a vaccination appointment is an ideal way for a medical system to
maximise its vaccine stock and ensure that the benefits granted are as large as possible.
As for why the results in women were not significant, Dr Spiegel and her colleagues theorise
that sleep affects female response to vaccines too but that hormone interference,
driven by varying stages of the menstrual cycle, contraception and hormone-replacement therapies,
is probably altering immune response in profound and unknown ways that throw off the results.
It is a subject area that urgently needs more attention, argue the researchers.
Vaccines are an important tool in the world’s armoury against disease
and there is no getting around the fact that developing and administering them is a difficult and expensive process.
But patients could at least be encouraged to give their immune system a rest before getting jabbed.
It costs nothing, and could pay considerable dividends.