A new study suggests that immunity provided by influenza vaccines increases, if they are given in accordance with the body’s natural cyclical rhythm, reports BBC.

A research team led by Professor Janet Lord unveiled that the effectiveness of flu shots surges if they are given to men in the morning and women in the afternoon, notes the public broadcaster.

The London-based news portal learns that human immune system tends to get inert with age, reducing the effect of vaccination. BBC notes that flu jabs fail to provide complete protection against flu for around 30% of aged people, due to their indolent immune system.

For the purpose of study, the Medical Research Council team rescheduled the appointments of around 300 GP patients in Birmingham. Male patients were scheduled for vaccination in the morning hours, while women were asked to come for flu shots in the afternoon, learns BBC.

Variation in the response of vaccine with time of day was noticed by the researchers, one of the study authors told the web portal. Men responded better to the flu jab in the morning and women noted an improved effectiveness in the afternoon, said Professor Janet Lord.

Citing the findings of the research, the chief researcher told the news portal that reason behind the variation in response of flu shot with time is still unknown, adding that the response may be linked to hormones.

BBC learns that change in hormone levels in the body has a different effect on men and women, predicting it to be one of the reasons behind flu shots effectiveness. Hopeful about the research, Professor Janet Lord emphasises that it is important to find out ways to improve the vaccination response in aged.