How Well Your Immune System Works Can Depend On The Time Of Day

How Well Your Immune System Works Can Depend On The Time Of DayThe time of day that we are infected with a virus may determine how sick we get. baranq/ Shutterstock

When microorganisms – such as bacteria or viruses – infect us, our immune system jumps into action. It’s highly trained to sense and eliminate infections and clear up any damage caused by them.

It’s typically assumed our immune systems work the exact same way regardless of whether an infection occurs during the day or at night. But research spanning over half a century now shows our bodies actually respond differently at day and night. The reason for this is our body clock, and the fact that each cell in the body, including our immune cells, can tell what time of day it is.

Our body clock has evolved over millions of years to help us survive. Every cell in the body has a collection of proteins that indicate the time depending on their levels. Knowing whether it’s day or night means our body can adjust its functions and behaviours (such as when we want to eat) to the correct time.

Our body clock does this by generating 24 hour rhythms (also termed circadian rhythms) in how cells function. For example, our body clock ensures that we only produce melatonin as night falls, as this chemical makes us tired – signalling it’s time for sleep.

Our immune system is composed of many different types of immune cells that are continually patrolling the body looking for evidence of infection or damage. But it is our body clock that determines where those cells are located at particular times of the day.

Broadly speaking, our immune cells migrate into tissues during the day and then circulate around the body at night. This circadian rhythm of immune cells may have evolved so that immune cells are directly located in tissues at a time when we are more likely to be infected, primed for attack.

At night, our immune cells circulate around the body and stop off at our lymph nodes. Here, they build up memory of what was encountered during the day – including any infections. This ensures they can respond better to the infection the next time they encounter it.


 Get The Latest By Email

Weekly Magazine Daily Inspiration

Given the body clock’s control over our immune system, it’s hardly surprising to learn that some research has shown that the time we’re infected with a virus – such as influenza or hepatitis – can impact how sick we become. The exact timing is likely to differ depending on the virus in question.

Other research has also shown that the time we take our medicines can affect how well they work – but again, this depends on the drug in question. For example, since we make cholesterol when we sleep, taking a short-acting statin (a cholesterol-lowering drug) just before bedtime provides the most benefit. It’s also been shown that time of day impacts how well certain types of immune cells work.

Body clocks and vaccines

There’s also an increasing body of evidence showing vaccines – which create an immune “memory” of a particular pathogen – are impacted by our body clock, and the time of day that a vaccine is administered.

For example, a 2016 randomised trial of over 250 adults aged 65 and older showed having the influenza vaccine in the morning (between 9am and 11am) resulted in a greater antibody response compared to those vaccinated in the afternoon (between 3pm and 5pm).

More recently, people in the mid-twenties who were immunised with the BCG (tuberculosis) vaccine between 8am and 9am had an enhanced immune response compared to those vaccinated between noon and 1pm. So for certain vaccines, there’s evidence that early morning vaccination may provide a more robust response.

One reason for seeing improved immune response to vaccines in the morning may be due to the way our body clock controls sleep. In fact, studies have found that sufficient sleep after vaccination for hepatitis A improves the immune response by increasing the number of vaccine-specific immune cells which provide long term immunity compared to those who had restricted sleep following vaccination.

It’s still not fully understood why sleep improves vaccine response, but it might be because of how our body clock directly controls immune cell function and location during sleep. So for example, it sends the immune cells to our lymph nodes while we sleep to learn about what infections were encountered during the day, and to build a “memory” of this.

Of course this raises the question of how this might all relate to the current pandemic and worldwide vaccination programmes. How our immune body clock works might be important in terms of whether we develop COVID-19. Intriguingly, the receptor which allows the COVID virus, SARS-CoV-2, to gain entry into our cells is under control of our body clock.

In fact, there are higher levels of this receptor on the cells which line our airways at distinct times of day. This could mean we’re more likely to get COVID-19 at certain times of the day, but further research will be needed to determine whether this is the case.

Whether the time of day we’re vaccinated against COVID-19 impacts immune response remains to be answered. Given the high effectiveness of many COVID-19 vaccines (with both Pfizer and Moderna reporting over 90% efficacy) and the urgency with which we need to vaccinate, people should be vaccinated at whatever time of day is possible for them.

But current and future vaccines which do not have such high efficacy rates – such as the flu vaccine – or if they’re used in people with poorer immune response (such as older adults), using a more precise “timed” approach may ensure better immune response.The Conversation

About The Author

Annie Curtis, Senior Lecturer, Medicine and Health Sciences, RCSI University of Medicine and Health Sciences


Recommended Books: Health

Fresh Fruit CleanseFresh Fruit Cleanse: Detox, Lose Weight and Restore Your Health with Nature's Most Delicious Foods [Paperback] by Leanne Hall.
Lose weight and feel vibrantly healthy while clearing your body of toxins. Fresh Fruit Cleanse offers everything you need for an easy and powerful detox, including day-by-day programs, mouth-watering recipes, and advice for transitioning off the cleanse.
Click here for more info and/or to order this book on Amazon.

Thrive FoodsThrive Foods: 200 Plant-Based Recipes for Peak Health [Paperback] by Brendan Brazier.
Building upon the stress-reducing, health-boosting nutritional philosophy introduced in his acclaimed vegan nutrition guide Thrive, professional Ironman triathlete Brendan Brazier now turns his attention to your dinner plate (breakfast bowl and lunch tray too).
Click here for more info and/or to order this book on Amazon.

Death by Medicine by Gary NullDeath by Medicine by Gary Null, Martin Feldman, Debora Rasio and Carolyn Dean
The medical environment has become a labyrinth of interlocking corporate, hospital, and governmental boards of directors, infiltrated by the drug companies. The most toxic substances are often approved first, while milder and more natural alternatives are ignored for financial reasons. It's death by medicine.
Click here for more info and/or to order this book on Amazon.


This article is republished from The Conversation under a Creative Commons license. Read the original article.

 

You May Also Like

AVAILABLE LANGUAGES

enafarzh-CNzh-TWnltlfifrdehiiditjakomsnofaptruessvtrvi

follow InnerSelf on

facebook icontwitter iconyoutube iconinstagram iconpintrest iconrss icon

 Get The Latest By Email

Weekly Magazine Daily Inspiration

Marie T. Russell's Daily Inspiration

INNERSELF VOICES

Healing Otherness: Your Changes, Reflected in Community
Healing Otherness: Your Changes, Reflected in Community
by Stacee L. Reicherzer PhD
Seeking out a community of healing, being exploited in it, perhaps assuming the shame and…
Horoscope Week: June 14 - 20, 2021
Horoscope Current Week: June 14 - 20, 2021
by Pam Younghans
This weekly astrological journal is based on planetary influences, and offers perspectives and…
Being A Better Person
Being A Better Person
by Marie T. Russell
"He makes me want to be a better person." As I reflected on this statement later, I realized that…
Modeling Behavior is the Best Teacher: Respect Must Be Mutual
Modeling Behavior is the Best Teacher: Respect Must Be Mutual
by Carmen Viktoria Gamper
Socially respected behavior is learned behavior and some of it (for instance, table manners) varies…
Separation and Isolation vs. Community and Compassion
Separation and Isolation vs. Community and Compassion
by Lawrence Doochin
When we are in community, we automatically fall into service to those in need because we know them…
The Only Easy Day Was Yesterday
The Only Easy Day Was Yesterday
by Jason Redman
Ambushes don’t just happen in combat. In business and life, an ambush is a catastrophic event that…
A Season for Everything: The Way Our Ancestors Ate
A Season for Everything: The Way Our Ancestors Ate
by Vatsala Sperling
Cultures on every continent around the world have a collective memory of a time when their…
How to Build New Bone... Naturally
How to Build New Bone... Naturally
by Maryon Stewart
Many women assume that when their menopause symptoms stop, they are on safe ground. Sadly, we face…

MOST READ

How to Build New Bone... Naturally
How to Build New Bone... Naturally
by Maryon Stewart
Many women assume that when their menopause symptoms stop, they are on safe ground. Sadly, we face…
image
IRS hitting you with a fine or late fee? Don't fret – a consumer tax advocate says you still have options
by Rita W. Green, Instructor of Accountancy, University of Memphis
Tax Day has come and gone, and you think you filed your return in the nick of time. But several…
How Well Your Immune System Works Can Depend On The Time Of Day
How Well Your Immune System Works Can Depend On The Time Of Day
by Annie Curtis, RCSI University of Medicine and Health Sciences
When microorganisms – such as bacteria or viruses – infect us, our immune system jumps into action.…
A teen reads her phone with a confused look on her face
Why teens have a hard time finding truth online
by Stanford
A new national study shows a woeful inability by high schoolers to detect fake news on the internet.
Planning the Burial: Anticipating Possible Problems and Blessings
Planning the Burial: Anticipating Possible Problems and Blessings
by Elizabeth Fournier
In addition to the emotional and spiritual aspects of funerals, there are always logistical and…
image
The mystery of long COVID: up to 1 in 3 people who catch the virus suffer for months. Here's what we know so far
by Vanessa Bryant, Laboratory Head, Immunology Division, Walter and Eliza Hall Institute
Most people who get COVID suffer the common symptoms of fever, cough and breathing problems, and…
An Open Letter to the Entire Human Family
An Open Letter to the Entire Human Family
by Ruchira Avatar Adi Da Samraj
This is the moment of truth for humankind. Critical choices must now be made in order to protect…
Turning 75
Turning 75: A Magic State of Wonder
by Barry Vissell
This month (May 2021), both Joyce and I turned 75. When I was younger, 75 years old seemed ancient.…

New Attitudes - New Possibilities

InnerSelf.comClimateImpactNews.com | InnerPower.net
MightyNatural.com | WholisticPolitics.com | InnerSelf Market
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.