Allergen vaccines are complex mixtures of antigenic components produced by the extraction of naturally occurring source materials, which are known to vary considerably in composition. Without intervention, this variation will be reflected in the final products.
The purpose of standardization is to minimize both qualitative and quantitative variations in composition so that a higher level of safety, efficacy, accuracy, and simplicity in allergy diagnosis and allergy vaccination may be obtained. Standardization of allergen vaccines can never be absolute, but it can be improved progressively as new methodologies and technologies are developed and the understanding of the properties of the allergens and the immune responses of allergic patients is increased. (more…)
Cells participating in the cellular immune response are organized into discrete associated lymphoid tissues and organs which are spread through the connective tissues of non lymphoid organs. Lymphocyte cell are responsible for the specificity of the cellular immune response. Approximately 2 x 1012 lymphocytes constitute the mature lymphoid system in humans together with a variety of ‘accessory’ cells which include epithelial cells, monocyte or macrophages cells and other antigen-presenting cells. Accessory cells are neede both for the maturation and for the effector cells functions of lymphocytes. 
Bacteria cause 
