Atopic disorders: a vaccine around the corner?

The incidence and severity of atopic disorders, in particular asthma, is st eadily increasing at an alarming rate. Furthermore, no primary prevention m easure exists to date. However, recent results obtained from numerous anima l studies suggest that primary prevention in humans might be possible in th e near future. The most promising approaches include the induction of syste mic or local allergen-dependent or -independent T helper 1 (Th1) immune res ponses, through the use of killed bacteria (or components derived from them ), CpG oligodeoxynucleotides or plasmid DNA, and the induction of allergen- specific T-cell tolerance. Here, we review the data showing that animals ca n be protected from developing allergic Th2 responses by vaccination. Possi ble future use in humans and potential side-effects of the described vaccin ation strategies are discussed also.