Morning vaccinations may boost immune response

It may sound simple, but the key to improved vaccination efficacy may be the time of day that a vaccine is administered, according to a new report.

The study, “Morning vaccination enhances antibody response over afternoon vaccination: A cluster-randomised trial,” published in Vaccine, reveals that the immune system may be more receptive to vaccines earlier in the day.

Researchers enrolled 276 adults aged 65 years and up, and performed vaccinations against various strains of influenza on them in the morning and afternoon. Results indicated that antibody responses for two of the three influenza strains tested were higher when the vaccinations were administered in the morning.

The report references other studies in chronobiology that have suggested that time of day can affect immune response, including a study that identified circadian variations in responses to antigens in mice.

“It is possible that diurnal variations in immune cell responses and/or levels of hormones with immune modifying properties, such as cortisol or inflammatory cytokines, provide an advantageous period for vaccination responses to occur,” according to the report. “Therefore, adjusting the timing of vaccination may be a simple, cost neutral and effective public health intervention to improve vaccination responses, particularly in older adults. However, it is possible that the best time of day for vaccination may be different for different vaccines, as they stimulate different types of immune response for protection.”

Anna Phillips, PhD, MSc, BSc, professor of behavioral medicine at the University of Birmingham in the United Kingdom and one of the study authors, tells Medical Economics more research is needed to confirm the study findings on a broader scale, but she believes the initial data is strong enough support a recommendation for morning vaccinations.

“Patients should definitely try to get their vaccine in the morning; there is nothing to lose as there are no risks or costs attached to this,” Phillips says. “This is a free intervention that could seriously boost older adults’ vaccination response with no adverse effects. We shouldn’t need to wait for the definitive trial to check that the increased levels of antibodies relate to decreased disease risk-we know that’s what antibodies do given that is the point of vaccination, so we can this now. The introduction of morning vaccination clinics would be the aim.”

Phillips says morning vaccinations could be particularly effective for patients with poor antibody responses, like the elderly.

Future research will focus on how time of day affects vaccination success for the general population and how results may vary using different types of vaccinations.