Immunity is a concept which extends beyond the microscopic cellular base known in western science.  A person who is balanced in physical, mental and spiritual aspects is defined as a healthy person according to Ayurveda. Therefore, enhancement of the immune system includes elements that enriches body, mind and spirituality. 

It begins with a balanced daily routine and healthy food habits. This sets the base to the harmony of energy flow, supporting all biological mechanisms in the body to function at its best. Stress and anxiety, which is now an unavoidable part of daily life, has a significant impact on our immune system and health in general. Imbalances of the mind reduces the immunity and make you more vulnerable for sicknesses / imbalances. 

According to Ayurveda, all diseases originate either in the mind, through unwholesome thinking patterns and stress, or in the gut due to poor digestion. If you maintain good digestion by supporting your body with proper cleansing mechanisms and compatible food, you will be rewarded with a strong and healthy body. At the end of the digestion process, the nutritious juices absorbed by the body become the nurturing media of the whole body. 

Immunity in Ayurveda is identified as Ojas, which provides for a healthy body and mind, liveliness / happiness, passion, drive, and good strength, as well as prevention and protection against diseases. The concept of Ojas is described as that which is necessary for natural immunity against ailments and also it is the resistance against degeneration and aging. Put simply, stronger your Ojas the less likely you are to get sick, and slower will be your degenerative mechanisms. According to the Charaka Samhita, as bees collect honey from flowers and fruits, Ojas is collected in the body from diet, qualities of a person, their actions and behavior. Therefore, all factors of physical, mental and spiritual, oneness or humane qualities all contribute to a person’s Ojas. Enriched Ojas will reward you with glowing skin, luxurious hair, peaceful energy and emotions, pleasant body aroma, feeling rested and energized through the day and you will less likely catch diseases. As Ojas is a subtle form of nourishment, when strong it ensures that the person has well-nourished internal tissues, great stamina, sexual potency and will be gifted with great children. If your digestion is not working properly, it will produce Ama (toxins) which will be carried on to all tissues, reduce Ojas and create heaviness in body and mind.  

There are types of Ojas described in Ayurveda: 

Sahaja Bala – Inherent state of resistance
Kala Bala – Acquired, the immunity you will achieve by age and exposure
Yuktikrutha Bala – Immunity induced artificially by external yet rational means
 

Ayurveda introduces the word Vyadikshamathva, which is the ability to resist disease manifestation. It consists of two mechanisms:

Vyadhi bala virodhithva – The act of resistance to the strength of the disease
Vyadhi uthpadaka vibandhathva – Capability of inhibition of disease-causing pathogens
This works as a chain of several mechanisms. This strength is unique from person to person and is linked to one`s internal balance and constitution or dosha. Some of the vyadikshamathva you inherit from parents and some you develop later in life.  Fresh air and healthy food are mentioned as two main factors that nourishes vyadikshamatha. The resistance is linked to the current dosha or constitutional imbalance of the person. Any imbalance in the body or mind makes you more vulnerable to diseases. 

Ancient Ayurvedic texts explains the manifestation of diseases by pathogens and small pox, several skin diseases and fevers, conjunctivitis and tuberculosis are also mentioned as contagious. Epidemics and spreading diseases through contaminated food, water and being exposed to sneezing, coughing and human contact are mentioned. Also, the fact that some animals who are carrier agents of diseases that can be transmitted to humans is also discussed in these ancient texts. In a crisis of an epidemic or a pandemic (Janapadaudwamsa), fumigation is highly recommended using ‘Rakshoghna Dravya’ to eliminate ‘bad spirits’. Nowadays we can relate this to the microbial organisms / cause of airborne diseases, virus and bacteria, etc. White Mustard (Sinapis alba), Asafetida (Ferula assa-foetida), Agil (Erythroxylum monogynum), Dead wood (Shorea oblongifolia), Vacha / Sweet flag (Acorus Calamus) and Neem (Azadirachta indica) works effectively in external use for fumigation and cleans / sterilizes the air or objects. A small bundle of these herbs in a powder form or as a paste can be wrapped around the wrist or worn in a pendant to enhance immunity. 

Herbal wash or bath can be used to kill external germs. Washing body, objects, wounds, floor surface using Turmeric (Curcuma longa), Nyagrodha (Ficus bengalensis), Udumbara (Ficus glomerata), Asvattha (Ficus religiosa), Parisa (Thespesia populnea) and Plaksa (Ficus lacor) is recommended. It also includes gargling (kawalagraha) to wash away and kill germs in the oral cavity and throat. Using simple salt and black pepper powder and Holy basil (Ocimum sactum) leaves is recommended. 

Rasayana (rejuvenation) as well as Vajikarana (aphrodisiacs) both will nurture immunity. Ayurveda recommends regular intake of herbs which boost immunity and keep tissue nourishment at optimal level. Indian Gooseberry / Amla (Emblica officinalis) is the best rejuvenating fruit and it is filled with antioxidants, creating a very potent immune booster as well as a metabolic enhancer. Rejuvenating formulas made using these type of herbs, like the compound Chyavanaprashavaleha, can single handedly ensure your tissue nourishment and provide great contribution to immunity. Guduchi (Tinospora cordifolia) is another good option for immune boosting and liver function. Brahmi (Bacopa monnieri)is a great immune enhancer and extremely beneficial to enhance Ojas production, promoting complexion, energy and immunity. 

Ashwaganda (Withania somnifera) has an excellent strengthening effect on the whole hormonal system and is a great aphrodisiac.  Turmeric (Curcuma longa) is a commonly used kitchen spice and quite famous for its anti-inflammatory action. It takes part in various immune boosting formulas in Ayurveda as well as traditional Sri Lankan Medicine. It is also commonly used as a disinfectant because of its antiseptic properties. 

Daru Haridra (Coscinium fenestratum) (Weniwel in Sri Lanka) is known as the Ayurvedic equivalent of paracetamol.  It has potent anti-inflammatory properties and anti-pyritic properties. It is a great immune booster and effective for sore throat and common flu up to tetanus. Sri Lankan Traditional Medicine, which is quite similar to Ayurveda, explains that the power of weniwel decoction is transmited through breast milk and whenever an infant has flu-fever related symptoms decoction of weniwel is given to the mother and the infant heals. 

Neem (Azadirachta indica) is a star in anti-microbial herbs in Ayurveda. The whole neem tree is used and it is a great antiseptic, speeding healing processes internally and externally. Neem oil is a strong cleanser in Sri Lankan Traditional Medicine and quite commonly used in treatment of cancer to enhance elimination of toxins effectively. 

Considering the nature of unaccountable number and varieties of microbes around us, human race has managed to survive and grow thanks to the immunity that the nature has gifted us. If we be mindful and pay attention, nature have offered many possibilities to keep us safe.