Remarkably, the nanobody trimer’s distinct potency to inhibit polyclonal IgE binding to Bet v 1 and tree relatives comparable to reported Bet v 1-specific monoclonal IgG antibodies and its pronounced suppression of IgE-triggered basophil degranulation corroborated a prospective application of protective nanobodies to treat allergy. This evidence concerns the gene IGHE and Allergy.