Abstract: The invention pertains to a process for the production of a pharmaceutical composition effective for controlling in a recipient mammalian host, particularly man, immune reactions of the type that are involved in graft of foreign tissue or cells, particularly transplantation of foreign tissues, organs or cells, particularly of allogeneic or even xenogeneic origin, or in immunodeficiency-linked diseases, which pharmaceutical composition is characterized by an active principle consisting of pooled transferrin-derived glycans obtained from a number of donors sufficient to allow the pool to contain sufficient phenotypic information required to ensure an induction of tolerance against antigens in an immuno-depressed host grafted with said antigens, after that host had been administered an amount of such pooled transferrin glycans effective to induce said tolerance.