Immunity means adequate biological defense to fight untoward invasion to keep body in balanced state. It is barrier or eliminator of many of pathogens entering in normal physiological bodies. It may be innate or adaptive. Innate is non-specific mechanism of defense which works immediately coming in contact of antigen. While adaptive one is antigen-specific defense working through recognition of specified antigen. Genes play an important role in immunity development through guiding the specific function of body and that affects immunity. Gene expression is related to roadmap of regulatory networks in immune cells. Studies indicate that transcriptional regulation is associated with control of gene expression in various immune cells, both adaptive and innate. RNA polymerases are receiving signals from cells and changing transcriptional programs. Studies are still to be done for effects of diets, immunity boosters, minerals, vitamins etc. in transcription. However, many investigations under nutritional genomics are present to illustrate the relationships of micronutrients and macronutrients with DNA, its damage and repairing. It means diets and life-style may have greater influences for ramifications of immunity through genes. Ayurveda has always advocated for life-style and diets for proper functioning of physiological body with better defense mechanisms.
Vyadhikshamtva is synonymous word for immunity suggested by many of authors in Ayurveda. Literally it also means capacity to fight or tolerate diseases. It depends upon the Ojas, Agni, Bala and Kapha of individuals. Luxurious life-style with less physical works, unwholesome food, emaciated or malnourishments etc. are considered as common cause of weakening Ojas, Agni, Bala and Kapha. According to Charak Samhita Chiktsasthana 1/1-2, Rasayana therapy is suggested against ageing and diseases as well as for promoting longevity. The concept can be understood in terms of immunity booster or enhancers. Amalaki, Haritaki, Haridra, Vacha, Dashmoola, Pippali etc. are mentioned as Rasayana drugs. These drugs are suggested according to specific individual body, age-groups, season, diseases, effects etc. A detailed study in connection with impressions of gene through these herbs is need of time from immunity points of views.