ONLINE COVER Averting Anaphylaxis. The cover image shows peanut butter and peanuts, both of which can cause anaphylaxis in peanut-allergic individuals. Strict dietary avoidance is the primary strategy to prevent anaphylaxis in those with food allergies, though accidental exposures can occur. Here, Alakhras et al. aimed to specifically prevent peanut allergen–driven responses in mice such that subsequent peanut exposure would not result in anaphylaxis. The authors developed a peanut Ara h 2 allergen-specific covalent heterobivalent inhibitor (cHBI) that blocked IgE-driven allergic responses. cHBI treatment prophylactically and therapeutically prevented anaphylaxis in peanut-sensitized humanized mice, with protection lasting as long as two weeks after cHBI treatment. These results highlight the potential clinical use of cHBI treatment as a preventative for peanut-specific allergic responses.