Hypoallergenic Vaccine may Ease Birch Pollen Allergies
Vienna - A hypoallergenic vaccine derived from genetically engineered birch pollen can reduce patients' allergic response to the pollen, according to Austrian researchers. A research team around Rudolf Valenta engineered the main birch pollen antigen, Bet v1, to be hypoallergenic and used it for vaccination of 124 patients over the course of one year. Individuals received the vaccine once before the peak of the birch pollen season, and were then screened throughout the year for IgE antibodies that cause allergic reactions by releasing inflammation mediators.
The immunologists found a 50% decrease in both IgE antibody and IgE memory cells together with a significant improvement of symptoms and increased levels of so-called IgG antibodies. They also found that the IgG level and the improvement of symptoms were dose-dependent. They speculate that the IgGs compete with the IgEs on the same antigen epitopes of the pollen, thereby providing a protective effect against rapid allergic reactions. The results of the clinical trial clearly indicate that the vaccine is capable of reducing the allergic response to future exposures to birch pollen. Valenta and his team also report fewer allergic side effects from the new vaccine. The authors indicate that hypoallergenic vaccines can be created with genetic engineering technology, or another recombinant DNA technology, to treat many common allergies known to affect more than 25% of the population in the industrialized world.