The invention relates to a process for the preparation of hypoallergenic major birch pollen allergens by means of one or more chromatographic purification steps using essentially unbuffered aqueous bases as eluent and subsequent neutralization. The hypoallergenic major birch pollen allergens are distinguished by a lack of, but at least by reduced immunoglobulin E binding with simultaneous retention of therapeutically relevant T-cell stimulation. They can therefore be employed as low-side-effect therapeutic agents for specific immunotherapy.
