Vaccines targeting IgE in the treatment of asthma and allergy.

Allergic diseases including asthma are characterized by an increase of serum IgE levels. Since IgE was discovered in 1966, it has been considered to be the most important biological target in the treatment of allergy and asthma. Indeed, recent studies reveal that IgE, through its high affinity IgE receptors (FcepsilonRI), is now considered a critical regulator of Th2 responses. This is supported by the great success of the anti-IgE monoclonal antibody (mAb) in the treatment of allergy and asthma. Nonetheless, adverse reactions such as anaphylaxis, urticaria and serum sickness have been reported with this therapy and repeated injections at extremely high costs are required to maintain effectiveness. To overcome these disadvantages, a new strategy using vaccines against IgE that may offer long-term efficacy with fewer adverse effects is being investigated. This article reviews IgE's role in allergy and asthma, currently used anti-IgE mAb omalizumab, and the advantages, types, effectiveness and development stages of vaccines against IgE. This review also discusses concerns with the vaccine strategy.