Chronobiology Reveals Flu Shots Taken in the Morning May Be More Effective

Influenza is even now a major risk to public health and ways to reduce its effect are regularly being investigated. The outcomes of a research performed at the University of Birmingham, UK, indicate that the effectiveness of a vaccine may change depending on the time of the day that it is administered. The results could have large implications for at-risk populations.

Even though there are huge scale seasonal vaccination programs in many nations, globally, flu is considered to be the cause of 250,000-500,000 deaths per annum.

One of the very vulnerable groups are people aged 65 and above. In the developed world, they account for the greatest number of hospitalizations and deaths from flu.

As we get older, our immune system can battle to generate the necessary levels of antibodies in response to a threat.

This is also the case for vaccinations; in elderly individuals, the reaction to a vaccination does not usually spur the immune system to generate sufficient protective antibodies.

In the developed world, schedules are in place to make sure that at-risk individuals have accessibility to the flu vaccine. This is specifically targeted on the above 65’s, but, regardless of a concerted effort, only about 50 percent of the shot’s recipients generate sufficient antibodies to become completely protected.

Numerous methods have been tested to increase reactions to flu vaccines, which includes exercise regimes and pharmaceutical additives. So far, not one has shown much success.

Chronobiology  strikes  a  responsive  chord.

Over the last few years, a new area of medical science has come to the fore: chronobiology. This field researches the difference  in the way our body’s biological systems react  during the course of a day.

Chronobiology study has shown that there are fluctuations in the way the immune system reacts to difficulties across a 24-hour period. For example, a horse vaccine that prevents encephalomyelitis was identified to generate peak levels of antibodies faster if it was provided in the morning, in comparison with the evening.

Another research identified that a hepatitis B vaccine triggered a stronger antibody reaction when given between 1 to 3 pm, in comparison with a 7.30 to 9 am time slot.

A group of investigators from Birmingham, U.K, led by Dr. Anna Phillips, set out to examine whether simply changing the time of day at which an individual obtained a flu shot could influence its success rate. Dr. Phillips describes:

“We know that there are variations in immune reactions throughout the day and desired to analyze whether this would increase to the antibody reaction to vaccination.”

The group had taken data from 24 doctor’s offices while in the U.K influenza vaccination program of 2011. In overall, 276 people were vaccinated, either during their morning hours (9-11am), or the afternoon hours (3-5pm).

Morning vs. afternoon vaccinations

The investigators identified that for 2 out of the 3 flu strains, a variation in reaction was measured. People who obtained the vaccination in the morning produced a considerably larger increase in antibody concentrations  1 month following the injection than individuals who obtained it during the afternoon.

For the 3rd flu strain, there was no variation between the afternoon and morning slots.

Chronobiology investigators expect various strains of pathogens to respond in a different way, but finding that two of the strains revealed an enhanced reaction is encouraging. Dr. Phillips says:

“Being capable to see that morning vaccinations produce a more powerful reaction will not only assist in approaches for flu vaccination but might offer clues to enhance vaccination strategies more commonly.”

Even though the outcomes are intriguing, the present research used a comparatively small sample, so the researchers are fast to call for more research. The group plans to increase their study to examine this possible vaccination timing effect on people with existing conditions, like kidney disease and diabetes.

If future outcomes mirror those of the pilot research, by simply changing the times of day that vaccinations are provided, lives could be saved. In addition, the modifications essential to roll this out will come at a minimal cost to healthcare providers.