Safety and efficacy of mannan-conjugated birch pollen allergoids in birch pollen-allergic adults

Birch pollens are tiny particles released by birch trees, especially in spring. They are one of the most common airborne allergens during the spring season. Mannan-conjugated birch pollen allergoids are modified birch pollen allergens designed for allergy immunotherapy. They are chemically altered (allergoids) and conjugated with mannan, a sugar molecule derived from yeast, which enhances the immune response while reducing allergenicity, important for desensitization therapies. Recent research demonstrated that all doses of mannan-conjugated birch pollen allergoids are safe, and the application of 10,000 mTU/mL was the most effective. The results of this study were documented in the journal Allergy.

In this study, 246 adults with birch pollen allergies received either a 0.5 mL of placebo or varying concentrations (1000 mTU/mL, 3000 mTU/mL or 10,000 mTU/mL) of the allergoids at five pre-seasonal visits. The efficacy of the treatment was evaluated by monitoring allergic symptoms and anti-allergy medication use during the peak of the 2020 birch pollen season. Additionally, tolerability, immunological, and safety outcomes were analyzed.

At the peak of birch pollen season, the highest dosage of mannan-conjugated birch pollen allergoids reduced the combined symptom and medication score by a median of 24.7% compared to the placebo. Bet v 1 specific IgG4 production significantly increased in a dose-dependent manner, with a 3.6- and 4.5-fold rise in the 3000 mTU/mL and 10,000 mTU/mL groups, respectively. The Bet v 1 specific IgE/IgG4 ratio was also greatly reduced (up to -70%). There were no fatalities or serious adverse events reported, and no adrenaline was administered. A total of four systemic reactions occurred, with two being grade I and two grade II.

Thus, it can be concluded that all doses of mannan-conjugated birch pollen allergoids are safe, and the application of 10,000 mTU/mL has been found to be the most optimal in terms of efficacy.