According to Ayurveda text, the natural immunity of an individual may be categorized into three types depending upon the Vyadhikshamatva (resistance against disease) and Bala (strength) of an individual.
The three kinds of Immunity
This is the constitutional immunity of an individual. This is the innate strength that is gained in the form of a foetus at the time of fertilization. It is supported by the natural factors of the health and strength (immune power) of the sperm of the father and ovum of the mother, the quality of place and time during the period of conception.
This is mainly the temporal invulnerability that an individual gains naturally in his lifetime; pertaining to factors like young age, following of good moral character and the right seasonal support.
Yuktija is the acquired immunity that can be gained by virtue of making positive changes in the aahara (diet pattern) and vihara (everyday lifestyle). There are a number of Ayurveda herbal formulation and natural herbs that would be extremely supportive in building the acquired immune power.
How to build your Natural Immunity
Ayurveda believes that a happy disposition of the mind reinstates natural immunity in the body making it to work as barrier against disease. Ayurveda lays emphasis on Satvic temperament of the mind which attributes to strengthening the individual on physical, psychological and spiritual grounds.
Also, being physically fit and energetic evokes your body and mind the effectual Karma for the state of natural wellbeing.
Yoga is one of the best existing forms of physical exercise recommended for immunity building.
Other than this Ayurveda relates the virtues of natural inbuilt resistance to factors like birth in a healthy environment, the time of the year which would be naturally strengthening and the innate physical constitution and mental temperament.