People with peanut or shellfish allergies can have their lives threatened just by kissing a partner who ate the problematic food. A path has opened to prevent deadly allergies that one-third of the world's population experiences with a vaccine. There are antibody treatments, but they are expensive and require frequent dosing, whereas the vaccine can provide protection for more than a year with two shots.
A team led by Laurent Reber at the Pasteur Institute said a vaccine targeting immunoglobulin E (IgE) antibodies prevented anaphylaxis, a severe allergic reaction, for 52 weeks in mice, according to a paper published on the 3rd (local time) in the journal Science Translational Medicine.
◇ Blocking antibodies that turn medicine into poison
The team modified mouse genes so that, like humans, they would trigger a severe allergic reaction when a specific substance entered the body. They administered the vaccine twice to mice to induce the body to produce another antibody that binds to IgE antibodies. In the experiments, even when an allergen was administered, the mice developed only mild allergies and their lives were not at risk.
In contrast, 8 of 9 unvaccinated mice died within 30 minutes of exposure to the same allergen. After vaccination, antibody levels in the blood were maintained for 52 weeks, showing a preventive effect.
IgE antibodies normally take part in immune responses. When pathogens or foreign substances enter the body, IgE antibodies bind to immune cells such as mast cells or basophils and send an intrusion alert. Mast cells secrete histamine to rouse the immune system. Blood vessels then dilate and blood rushes in, mobilizing immune cells en masse.
But medicine in excess becomes poison. If the immune response becomes excessive, the tongue and throat can swell and block breathing, and vasodilation can drop blood pressure and cause fatal shock. That is anaphylaxis, a severe allergic reaction.
The French team developed an IgE kinoid conjugate vaccine that blocks anaphylaxis by linking three protein fragments of the IgE antibody to a carrier protein called CRM197. When this vaccine is given, the immune system is trained in advance to regard IgE as an external invader. Later, when IgE antibodies appear, other antibodies immediately latch on and prevent them from binding to immune cells. That blocks histamine release from immune cells and prevents severe allergic reactions.
The vaccine uses the same principle as Xolair (omalizumab), an allergy treatment developed by Genentech in the United States and Novartis in Switzerland. Xolair is an antibody therapy that binds to IgE. But the drug is very expensive and its effects are temporary, requiring frequent dosing.
The newly developed vaccine avoids those issues because it induces the body to continuously produce antibodies that work like Xolair. The adrenaline injector EpiPen can also relax muscles and constrict blood vessels to prevent allergic shock, but it is not a fundamental treatment.
◇ Normal immune responses against parasites stay intact
IgE can cause allergies but also blocks other pathogens such as parasites. If the vaccine were to block IgE's normal functions, it could harm the body. Fortunately, the vaccine did not block the antibody's normal immune responses. The team said in mouse experiments the vaccine did not hinder IgE antibodies' parasite clearance.
Reber said clinical trials in humans are needed to evaluate the vaccine's safety, efficacy and duration, and noted that if commercialized, treatment could be possible with far fewer injections than anti-IgE monoclonal antibodies like omalizumab, making it a cost-effective option for patients with severe allergies.
A team led by Joshua Koenig at McMaster University in Canada also wrote in a commentary published in the same journal that thanks to its advantage of strongly suppressing anaphylaxis without side effects, the IgE kinoid vaccine is a highly attractive therapeutic candidate, adding that the vaccine developed this time is likely to be effective in people.
If the vaccine succeeds, it could create a massive market. Xolair, an anti-IgE antibody therapy, was approved by the U.S. Food and Drug Administration (FDA) for asthma in June 2003 and has continued to expand its indications. Beyond asthma, it is used to treat various allergic conditions such as hives and sinusitis, generating nearly 6.5 trillion won in global sales last year.
With Xolair's patents expiring in Europe and the United States in October and November, respectively, a wave of biosimilar development began. In Korea, Celltrion developed Omlyclo, the first biosimilar to Xolair, and won approvals in Europe and the United States.
References
Science Translational Medicine (2025), DOI: https://doi.org/10.1126/scitranslmed.ads0982