Researchers in France have developed a vaccine that protects mice against anaphylaxis, a severe and life-threatening allergic reaction. This work could inform the development of new treatments for people with severe allergies.

Allergic reactions occur when allergens, such as peanut proteins, attach to a type of antibody called Immunoglobulin E (IgE). IgE sits on the surface of immune cells and, when activated, triggers the release of substances that cause allergy symptoms, including anaphylaxis. Current treatments like Omalizumab help many patients by reducing IgE levels, but one-third of people with food allergies do not respond to it.

The team at Institut Pasteur created a vaccine that prevents IgE from binding to immune cells, stopping the allergic reaction before it begins. To test its efficacy, they used mice genetically modified to produce human IgE (instead of mouse IgE) and to develop peanut allergies. 

After exposure to peanut proteins, vaccinated mice had weaker immune reactions and fewer signs of anaphylaxis, such as drops in body temperature. While 80% of unvaccinated mice died following exposure, all vaccinated mice survived, with no harmful side effects observed. 

Unlike existing treatments that require regular administration, a single vaccination protected mice for at least 12 months. The authors of the study published in Science Translational Medicine suggest this approach could offer a more convenient, longer-lasting way to manage severe allergies in humans.