The NHS rollout of the covid-19 vaccine is continuing at a remarkable pace, with almost 78% of the UK population having received one dose, and 55% fully vaccinated with two doses. But i f you haven’t yet received your first vaccine, or are waiting for a second, you may be wondering what else you can do in the meantime to help protect against new variants of the virus.
Respecting social distancing rules, wearing face masks and hand washing can all help to prevent the virus getting in, but if you ARE exposed to the virus, your odds of staying fighting fit will depend on the strength of your immune system.
So how do we protect the immune system?
Research has found that we can reduce our risks of infection by:
- minimising stress
- a healthy nutrient rich diet
- not smoking
- avoiding excess alcohol
- regular exercise
- exposure to sunlight
.. and.. the one I’m really excited about... plenty of sleep!
Does more sleep reduce your odds of getting a viral illness?
In a study by Prather and colleagues (2015), 164 healthy adults tracked their sleep patterns at home for 7 nights, using a wrist monitor to record how long they slept. They were then invited to a hotel where they were isolated for 5 nights. On day 1 of their 'vacation', they were administered nasal drops containing the common cold virus, and researchers followed up to see who developed a cold.
Researchers found that 76% became infected with the virus, and 29% had a biologically verified cold. The risk of developing a cold was more than 4 times higher for those who slept for less than 6 hours than those who slept for 7 hours or more.
In fact, short sleep was a stronger predictor of risk for infection than all the other characteristics measured, including age, BMI, education, smoking, alcohol, stress and mood.
What’s the link between sleep and immune function?
Your immune defences consist of several different varieties of white blood cells - the foot soldiers in the fight against invaders into the body. First the scouts have to recognise foreign bodies, or antigens, and tag them so that the rest of the immune system can spot them. Invaders are often escorted to the body’s lymph glands so they can be outnumbered and destroyed. Some cells help recognise antigens for a speedy response in the future, i.e. by producing specific antibody, which can multiply rapidly if we see the same infection twice.
How does sleep make a difference? Studies in the lab have found that even one night without sleep can interfere with communication between immune cells, making the whole army less efficient, and causing more collateral damage, in the form of inflammation. Inflammation can be part of a healthy response to infection, but too much of it has been linked to chronic diseases, such as heart disease.
Sleep seems to be particularly important for T cell function. T cells help to identify invaders, send out cytokines (messengers) to tell the rest of the army what’s up, and do the work of destruction. Restricting sleep to 4 hours in healthy people can reduce the activity of our ‘natural killer’ T cells by 28%.
How do vaccines help to support the immune system?
Vaccines like the coronavirus vaccine prime the immune system to recognise a virus, so that it can fire up an overwhelming antibody response if we get infected. In general, the stronger our immune system, the more likely we are to have an effective and lasting response to a vaccine. There hasn’t been any research looking at the coronavirus vaccine and sleep yet, so we don’t know for sure what role sleep plays, but other studies suggest that sleep could be important:
- Another study from Prather and colleagues (2012) found that after a Hepatitis B vaccine, >95% of those sleeping for 7 hours or more produced a clinically protective response, vs. <75% of those who slept for fewer than 6 hours before they received the vaccine.
- Those getting their usual 7 plus hours of sleep before and after a flu vaccine were twice as likely to have an effective antibody response than those whose sleep was restricted to 4 hours or less (Spiegel et al 2002).
So, what can you do to strengthen your natural defences against illness?
A 2016 study by RAND Corporation found that more than 1 in 3 of UK adults do not routinely get the recommended 7-9 hours sleep each night, so there could be a huge opportunity to strengthen the nation’s defences, simply by protecting time for sleep.
If you are looking for simple steps to protect your health..
- Try to protect at least 7 hours for sleep
- Wake up at a regular time, as often as you can
- Get outside and get active each day
- Allow time to wind down and relax before you get into bed
- Sleep somewhere cool, dark and comfortable
If you can protect time for sleep, it could help to protect you.