Your immune system is equivalent to your defence capacity. It is a collection of components and consists of complex, diffuse, and integrated intelligence network of organs (namely the skin and liver), tissues, blood cells (such as white blood cells) and cellular products (e.g. antibodies).

The entire system works together just like an army of specialized units, in a coordinated fashion around the clock to protect a person against microbes, toxins, poor lifestyle choices and even stress. The following advice is recommended:

Adequate Rest
Too much exertion and a lack of rest is known to weaken body resistance. Evidence from several studies demonstrate that insufficient sleep can slow down the immune system, reducing the ability to defend against infections.

Avoid Stress
Stress in the form of worry, anxiety or anger can effectively drain the immune system, making an individual more vulnerable. A study in 2012 reported that people with chronic stress are more likely to develop persistent cold symptoms than those who have less or no stress. Scientific studies have shown that chronic stress leads to excess production of the stress hormone cortisol, which is associated with negative effect on the inflammatory responses in the body.

Wash hands thoroughly and often
The basic practice of hygiene has been shown to make a major difference. It is recommended that we wash our hands with soap and water regularly and thoroughly. This simple and inexpensive practice is known to reduce respiratory illnesses such as colds and flu by 21%.

Consume a healthy Diet
A nourishing diet contains the right kinds and amounts of carbohydrates, proteins, and fats, with plenty of fruits and vegetables.
We know too much sugar is bad for health, but a diet rich in processed sugar can also weaken the immune system. Too much sugar can prevent phagocytosis, a process by which viruses and bacteria are destroyed by white blood cells. In keeping with healthy habits, it is important to ensure alcohol consumption in moderation, cutting down on smoking and undertaking mild to moderate amounts of exercise at home.

Implement social distancing
The simple measure of avoiding crowds and gatherings has proven to reduce the risk of transmission of the virus. This is why several countries have imposed a lockdown in an attempt to contain the spread of the virus.

Consider taking a supplement of Vitamin D
It may be advisable to soak up some sunshine in moderation. The skin has the natural ability to convert sunlight into vitamin D, an important nutrient that serves many functions in the body, including a crucial role in boosting the immune system and protecting against upper respiratory infections, including the common cold, flu, and pneumonia.

A supplement with 2,000 to 5,000 IU of vitamin D3 daily can also help.

Other nutritional supplements that can bolster the immune system are as follows:

• Multivitamin and minerals
• Vitamin C
• Resveratrol; found naturally in the skin of red grapes is thought to help prevent virus replication in the recommendation dosage of 50-200 mg a day.
• N-acetyl Cysteine (NAC); This is an important amino acid which acts as a building block for glutathione, which is thought to be a very useful antioxidant in the body. Research has shown that 1,000 mg a day can significantly decrease the frequency of influenza-like episodes, as well as severity and length of time confined to bed.

Prepared by:
Dr Reshma Ramracheya
Research Scientist & University Research Lecturer at the University of Oxford
Senior Research Fellow at Wolfson College, University of Oxford
Reshma.ramracheya@ocdem.ox.ac.uk