Scientists have developed an experimental vaccine that protects mice from life-threatening allergic reactions for at least a year. The vaccine, named IgE-K, targets immunoglobulin E antibodies to prevent anaphylaxis. Researchers hope it could offer long-term protection for humans with severe allergies.
Anaphylaxis poses a constant risk to millions worldwide, including about 2.4 million adults in the UK with confirmed food allergies. Triggers like peanuts or shellfish can cause a surge in IgE antibodies, leading to throat swelling, breathing difficulties, and blood pressure drops that may require hospitalization or prove fatal, even with tools like EpiPens.
Current prevention methods are limited. Oral immunotherapy builds tolerance through supervised exposure to allergens, while omalizumab, an anti-IgE monoclonal antibody, binds IgE but requires frequent, costly injections.
Laurent Reber at the Toulouse Institute for Infectious and Inflammatory Diseases in France led the development of IgE-K. This vaccine prompts the immune system to produce antibodies that block IgE from binding to receptors on immune cells, averting allergic overreactions.
"We wanted to come up with a solution that could be long-term, because when you are food allergic, you can be exposed anytime by accident, so you really want to be protected all the time," Reber explained.
In experiments, two doses given to mice engineered to produce human-like IgE generated neutralizing antibodies. When exposed to an anaphylaxis-inducing substance, unvaccinated mice reacted severely, but vaccinated ones showed no symptoms for a year, with no adverse effects observed.
"It blocks up the molecule that makes us allergic," said Josh Koenig at McMaster University in Ontario, Canada.
IgE also combats venoms and parasites, an ancestral defense mechanism, Reber noted. Tests confirmed the vaccine did not hinder mice's response to the parasitic worm Strongyloides ratti.
Koenig expressed optimism: "They know that the mouse made the antibody that bound up the human IgE molecule properly. If humans make that same molecule, then I think there’s a pretty high chance that this will work out quite nicely."
Reber emphasized the need for clinical trials to assess safety, efficacy, and duration in humans. If successful, IgE-K could provide a cost-effective alternative to ongoing injections like omalizumab. The findings appear in Science Translational Medicine (DOI: 10.1126/scitranslmed.ads0982).