During certain conditions or factors, even unwholesome food does not produce disease immediately. The variety of unwholesome food is not equally harmful in causing disease; all dosas are not equally powerful, and variations in physique and mind play a role in resisting disease. Variances in several genes can influence how well a patient might respond to a particular drug or antigen. Resistance to disease or immunity against disease is of two kinds i.e. one that attenuates the manifested disease and the other prevents the manifestation of disease.