An increasing number of hypoallergenic allergen derivatives is currently be
ing produced by genetic engineering as well as by synthetic peptide chemist
ry and evaluated as candidate molecules for specific immunotherapy of type
I allergy. One advantage of recombinant and synthetic hypoallergenic allerg
en derivatives is that they can be designed to simultaneously retain the im
munogenic/tolerogenic properties of the wild-type allergens and to exhibit
a strongly reduced allergenic activity, When used for immunotherapy, it may
be expected that hypoallergenic allergen derivatives will exhibit a lower
rate of anaphylactic side effects. Furthermore, hypoallergenic allergen der
ivatives can be used for component-resolved immunotherapy tailored accordin
g to the individual patient's sensitization profile. This chapter summarize
s strategies for the production and evaluation of recombinant as well as of
synthetic hypoallergenic allergen derivatives as candidate vaccines for ty
pe I allergy.