Well, for one this is a study in mice. It is a long way from becoming a commercial product and might not be translatable between mice and humans.

I am a bit skeptical about the allergen protection since in mouse models the mice are "being made" allergenic during the model duration. That is being blocked it seems. If that also means that if you already have the allergy, this new vaccine would block it going forward, hard to say. If one could vaccinate children with this, they may not develop such allergies though, which would be interesting!